Wikipedia talk:WikiProject Mathematics/Archive/2007

Jan 2007

Jasna Mađarević

Could someone take a look here? The article is about Serbian mathematician and is on AfD. TIA Pavel Vozenilek 02:32, 1 January 2007 (UTC)

Nonsense in Liber Abaci and Egyptian fraction

I'm getting very tired of repeatedly reverting Milo Gardner's changes (some under Milogardner (talk · contribs), some under various 172.x.x.x addresses) to Liber Abaci and Egyptian fraction, which I see as...not wrong exactly, but badly written, off-topic, giving undue weight to fringe points of view, and generally damaging to the usefulness and readability of the articles. And I'm a little worried that in doing so I'm becoming too single-minded myself and may be violating WP:OWN. Someone else want to give me a reality check, are his edits really as revert-worthy as I think they are? As an example, here is the diff from a sequence of 11 of his edits that I reverted with the somewhat abrupt summary "rv incomprehensible damage", which he took exception to. Was I too harsh? —David Eppstein 19:44, 1 January 2007 (UTC)

I don't have time to help out now, or in the coming days, but I'll just note that I had quite some problems with Milo on ancient Egyptian mathematics, see the talk page and also my user talk page. He obviously knows quite a bit about that, but he is unable to write it down in a format suitable for Wikipedia; specifically, his contributions are not neutral, but seem to be written in order to push certain theories which are not mainstream (e.g., remainder arithmetic). That's my own opinion, but it matches well with David's observations. -- Jitse Niesen (talk) 20:41, 1 January 2007 (UTC)

Without trying to follow the math, I observe that both articles contain a lot of derivations and many attempts to show the affinity of ancient and modern methods. Although we seem to tolerate a fair number of do-it-yourself derivations in the mathematics pages, strict application of policy would probably say that we should only repeat derivations published by others, and we should only make historical comparisons that have been published by others. On that view, both articles would probably become shorter. As to your specific revert in Liber Abaci, I have no complaints. The bibliography in Egyptian fraction looks huge, with many esoteric entries. Most of these are not cited in the text. It might perhaps be shortened by including a link to an online article with a good bibliography. EdJohnston 21:05, 1 January 2007 (UTC)

Gardner clearly has a lot of expertise on the subject, but his inability to write an intelligible sentence seriously detracts from the value of his contributions. I don't think you were too harsh. -- Dominus 23:52, 3 January 2007 (UTC)

Article listed for deletion

Wikipedia's mathematicians may wish to give their opinions at Wikipedia:Articles for deletion/List of books in computational geometry. Michael Hardy 01:54, 4 January 2007 (UTC)

Laplace-Runge-Lenz vector is now FAC

Hi, I just nominated Laplace-Runge-Lenz vector to be a Featured article candidate. Hopefully, you all think that the article is excellent and can support it. ;) But if not, please offer constructive criticisms on how it might be improved, which will be much appreciated. Thanks very much for your help! Willow 10:49, 31 December 2006 (UTC)

Is this not better described as Physics or Astronomy rather than Mathematics? JRSpriggs 05:23, 5 January 2007 (UTC)

Section Hyperreal number#Polynomial_ratio_construction

This section contains the following assertion

Let any relation of real polynomials in a single variable and their ratios hold when and only when they hold for all but a finite number of natural number values of the variable. The proof that first-order statements about polynomial ratios have the same truth value as corresponding first-order statements about standard real numbers is much the same as the proof for the ultrapower model, but requires only the use of a cofininite or Fréchet filter, not ultrafilters or the Axiom of Choice.

I find this dubious, although examination by a model theorist would be appreciated.--CSTAR 19:41, 3 January 2007 (UTC)

Hmmm. It's true for any infinite set of natural numbers, instead of merely all but a finite number of natural numbers. The result follows from the trivial result that any polynomial with an infinite number of roots is identically 0. I don't know if I could come up with a model-theoretic proof, though. — Arthur Rubin | (talk) 21:19, 3 January 2007 (UTC)

I can see how to reason thus if all the relations in question were elementary equations. If other relations, such as inequalities, are also considered, I'm less sure that it is trivial. Henning Makholm 22:45, 3 January 2007 (UTC)

It sounded what like he was saying that a particular mapping is an elementary equivalence embedding.

Your interpretation of this seems to be that for any n-ary relation R if I is an infinites subset of R

$R{\bigg (}{\frac {P_{1}(x)}{Q_{1}(x)}},\ldots ,{\frac {P_{n}(x)}{Q_{n}(x)}}{\bigg )},\quad \forall x\in I$

holds if and only if

$R{\bigg (}{\frac {P_{1}(x)}{Q_{1}(x)}},\ldots ,{\frac {P_{n}(x)}{Q_{n}(x)}}{\bigg )},\quad \forall x\in \mathbb {R}$

This is certainly true for polynomial relations (e.g. in case there is a polynomial Q for which

$R(s_{1},\ldots ,s_{n}){\mbox{ holds iff }}Q(s_{1},\ldots ,s_{n})=0$

But I don't think I understand what you said in general. Take

$n=1,P_{1}(x)=x,Q_{1}=1$

and

$R(s){\mbox{ being the unary predicate }}s>0$

x > 0 is true for an infinite set of integers, but it's certainly not true for all reals. Am I missing something?--CSTAR 21:51, 3 January 2007 (UTC) PS. Note also that the polynomial $x^{2}-x\geq 0$ for all integers x, but is negative in the open interval ]0,1[. --CSTAR 22:01, 3 January 2007 (UTC)

It makes more sense to me if read as: "If, for all choices of polynomials, the relation holds for an infinite (co-finte) set of integers (which may depend on the polynomials, then the relation holds for all reals". That is, you're supposed to take some closed formula and systematically substitute every quantification over reals into a quantification over polynomial ratios. So your counterexample is not a counterexample, because there are certainly polynomials for which $s>0$ do not hold for any integers at all. Henning Makholm 22:37, 3 January 2007 (UTC)

OK that I think I believe. There are still some details that need to be ironed out. Particularly, that this field is non-archimedean. But I guess the polynomial ratio x/1 will do the trick since for any (standard) integer n, x/1 - n > 0 holds. --CSTAR 22:54, 3 January 2007 (UTC)

This latter construction still doesn't look right; as x² != 2 is true for all rationals, (and hence all polynomials with integer coefficients evaluated over the integers), but not for all reals. Perhaps the only situations in which it makes sense is for polynomial equalities, in which case my first assertion is accurate. — Arthur Rubin | (talk) 14:04, 4 January 2007 (UTC)

OK this is even worse than I had originally thought; since it appears the language for which the mapping of the reals into polynomial ratios is an elementary embedding, cannot even include negation! --CSTAR 18:30, 4 January 2007 (UTC)

Hmm, it seems that trying to reason out the mathematical truth here is likely to confuse everybody, including every future editor who may try to figure out the claim. Let's revert to basic Wikipedia principles: we need to get a source for the claim, and then we can discuss whether the article accurately represents the claim made in the source. In the absence of sources, remove the claim. Henning Makholm 23:22, 4 January 2007 (UTC)

The complex plane

I've just finished adding quite a bit of new material to this article, which had been marked as a "stub". I would appreciate some feedback, either here or on my talk page. Is the article too long? Or just about right? I think this particular topic should be of some interest to the general reader, so I tried to keep it all as non-technical as I could. Does that approach make sense? Etc.

I could also use some advice on one thing. Rgdboer had raised a question about other meanings of the phrase "complex plane" on the article's talk page. So I added a section Complex plane#Other meanings of "complex plane" to discuss, briefly, the concepts of split-complex numbers, dual numbers, and the Cartesian product C×C. I'd like to write a little bit more for that section, but I'm not sure I understand these three objects well enough to figure out exactly what to say.

The first two "other complex planes" seem as if they'd hardly work well for analysis, except for some rather specialized applications in physics. And the two-dimensional vector space C×C is sort of tricky as well – right off the top of my head, I'm not even sure how to define a useful norm for that space. So I could use some help figuring out what else to say in that section of the article, if anybody here is willing to help.

Thanks! DavidCBryant 20:05, 6 January 2007 (UTC)

We have just been through a series of changes at Complex number#Conversion from the Cartesian form to the polar form concerning the computation of the argument of a complex number. The simplistic formula you give, $\theta =\arctan {\frac {y}{x}}$, is only correct when $x>0\!$. JRSpriggs 09:37, 7 January 2007 (UTC)

Thanks for pointing that out. I'm not sure what I was thinking; just absent-minded, I guess. I've changed it – you may or may not like this other idea, which is

$\theta =\arg(z)=-i\log {\frac {z}{|z|}}.\,$

I took a closer look at the article about complex numbers, and I'm not sure I agree with the way this problem is treated there. Maybe I'll jump in on that article's talk page. DavidCBryant 15:13, 7 January 2007 (UTC)

A bug?

I used to be able to reach the article Methods of computing square roots by going through the category Category:Root-finding algorithms. However, now when I look in that category, the article does not appear on my screen. None the less, the file has not been edited to remove it from the category. Nor has the category been changed in a way that would have that effect. Could this be a new bug in the software for displaying the contents of a category? Help! JRSpriggs 09:25, 7 January 2007 (UTC)

When I checked the category just now, the article was there (under M, of course). --KSmrq^T 12:13, 7 January 2007 (UTC)

I think it's working now. I removed an external reference to a web page right here that wouldn't respond when I pinged it. I'm not sure if the dead link was the problem, or if the Cyrillic characters displayed on the page were at fault, but the article shows up in the category list now. Oh -- why was the description of this site written in Russian? I can understand linking to foreign language web sites, but I don't understand why the link should be described in a foreign language on this end. DavidCBryant 12:30, 7 January 2007 (UTC)

PS to KSmrq – That's weird! I removed the broken link in the article, then sat here a while thinking about another problem before finally writing my response. The problem Spriggs reported was definitely showing up for me before I took the Russian language stuff out of the article. You checked the category while I was sitting here thinking about something else. DavidCBryant 12:37, 7 January 2007 (UTC)

Monty Hall problem

Monty Hall problem has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. Gzkn 10:57, 7 January 2007 (UTC)

The first reason cited for needing review? "Has one inline citation." Here we go again. --KSmrq^T 12:18, 7 January 2007 (UTC)

Collatz conjecture

I have seen a few references to a proof by this paper. It is listed in Québec Science's (ISSN 0021-6127) February 2006 special issue as one of the 10 top scientific breakouts made by Quebec scientists in 2006. Can somebody more knowledgeable than myself in maths look into that? Circeus 18:17, 10 January 2007 (UTC)

It doesn't prove the Collatz conjecture. What it does is to define a related probabilistic model in which a gambler, starting from an initial stake of A dollars, repeatedly flips a fair coin and based on the result replaces A with either A/2 or (3A+1)/2, and shows that this model leads almost surely to becoming broke. To me this seems very unsurprising. —David Eppstein 18:41, 10 January 2007 (UTC)

The paper requires a subscription, so I haven't seen it. What you describe seems to have a tenuous (or more accurately no) relation to the 3x+1 problem. It would seem to me, that to have some relation to the Collatz problem the parity of A should have some bearing on the next element of the sequence.--CSTAR 19:00, 10 January 2007 (UTC)

There is a free online paper by Alain Slakmon and Luc Macot. Also this online commentary (in French). My loose translation of Slakmon's summary:

"As we're talking about a probabilistic approach, we can't assert that there is an absolute proof of the truth of the conjecture. There remains a very small probability that certain numbers violate it," says Alain Slakmon. "But this possibility is now infinitely small". EdJohnston 19:45, 10 January 2007 (UTC)

Well, their solution is exactly as David Eppstein described it. I think that the commentary (CQFD) is hyperbole. I am very skeptical whether this really gets us any further to solution of this problem.--CSTAR 20:07, 10 January 2007 (UTC)

Missing articles

I was looking at the list of missing math articles at Wikipedia:Missing science topics/Maths1 and considering writing up some stubs (or perhaps a bit more) for a few topics, but it seems to me that many of these probably aren't sufficiently notable. For example, 0-free has an article on mathworld at Zerofree, and there seem to be one or two articles on it plus a sequence at the OEIS (which means nothing, really), but that probably doesn't satisfy the notability criteria. In fact, this is probably true of most of the terms in that list (even ignoring the ones that should probably be sections in other articles).

Am I right about this? Should I remove the links for topics that don't seem to be notable? Your opinions will be appreciated. --Sopoforic 02:39, 11 January 2007 (UTC)

Those lists are a compilation from such sources as MathWorld, PlanetMath, Springer's encyclopedia, etc. It is quite likely that a bunch of them are not notable. However, creating redirects to existing articles covering those concepts would be preferable to just removing those links from the lists I would think. Oleg Alexandrov (talk) 04:38, 11 January 2007 (UTC)

Well, sure, where possible. But in the example I cited, zerofree, we don't have any article to redirect it to. There are enough sources to make it verifiable, but it probably doesn't count as notable, in my opinion. My question is, granted that a thing is not notable, should I remove it from the list, or is it serving some greater purpose by being there? I was just going to remove such things, but I thought I should ask since I don't know if these lists are used for anything else than finding articles to write. --Sopoforic 14:37, 11 January 2007 (UTC)

You can remove unhelpful entries, no problem. The only issue is that when my bot updates those pages again, it may put those removed entries back. Perhaps, as you remove those entries, you could put them in a list for me, so that I make sure the bot remembers those and does not add them back the next time around. Oleg Alexandrov (talk) 17:11, 11 January 2007 (UTC)

An even better solution could be I think to just ignore the non-notable entries. It is very likely a good chunck of those redlinks will never turn blue. We could as well focus on the ones which are worth filling in and glossing over entries that don't appear relevant. Oleg Alexandrov (talk) 17:15, 11 January 2007 (UTC)

The problem with that is that if they are left on the list, other people will also have to evaluate them to see if they are notable, which is duplication of effort and ought to be avoided. --Sopoforic 17:39, 11 January 2007 (UTC)

This discussion got me curious enough that I went and reread the stuff about "Notability". Did you read the additional stuff at Wikipedia:Notability (numbers), Sopoforic? It looks as if "zero-free" might be notable, at least IMV. Oh – this reminds me of an old joke. Every positive natural number is unusual. The proof is by induction. Assume the theorem is false. Since the set of all positive natural numbers is bounded below, the set of all positive natural numbers that are not unusual must have an infimum x. But that's a pretty unusual property for x to have ... should we swap "unusual" with "not notable"?  ;^> DavidCBryant 17:26, 11 January 2007 (UTC)

Eh, the one that gives me difficulty is the first: "do mathematicians publish papers about it." Most anything that can be imagined will have one or two papers published about it, and zerofree only seems to have one that I'm sure is about that particular meaning (need to visit the library so that I can read the full text of the other articles). The notability guidelines generally go 'multiple non-trivial works' so I didn't think that just one paper was necessarily sufficient.

I suppose that I can just create articles for these and let AfD decide whether they're notable, should they be nominated for deletion, but I'd prefer not to waste effort. Still, it may be the best solution--I've probably already taken more time trying to decide whether zerofree was notable than I would have spent making a brief article on the subject. --Sopoforic 17:39, 11 January 2007 (UTC)

I prodded N-th triangular number squared a few days ago for notability. I would suggest prioritizing your new articles to create the most important ones first. It's a waste of everyone's effort to create articles if they are likely to be nominated for deletion quickly. CMummert · talk 17:48, 11 January 2007 (UTC)

While I agree that there are many non-notable items in these lists and many non-notable sequences in OEIS, I'm not convinced that N-th triangular number squared is a good example of such. The fact that the sum of consecutive cubes is a square, and moreover a square of a different important number sequence, is I think surprising and notable. OEIS gives seven references and a quick search found five more, including Stroeker, R. J., "On the sum of consecutive cubes being a perfect square", Compositio Math. 97 (1995), no. 1-2, 295--307, and Kanim, K., "The Sum of Cubes—An Extension of Archimedes' Sum of Squares", Proofs without Words, Mathematics Magazine, October 2004, 298-299. I don't have time to write more about this now (or fix up the article so that it is worthy of surviving your prod, which I think should include giving it a less cumbersome name — "squared triangular number" maybe?) but will try to take another look tonight. —David Eppstein 18:48, 11 January 2007 (UTC)

I agree that that article is on the edge of what is notable for a number and what is not; I happen to feel it is on the opposite side. Do you agree that a topic that is clearly more notable than that is notable enough? CMummert · talk 20:05, 11 January 2007 (UTC)

Yes. I also agree that the article as it stands isn't worth including; the bulk of the text (an easy inductive proof) is more filler than content. But I think it has potential to be above-threshhold. —David Eppstein 22:50, 11 January 2007 (UTC)

(The indenting gets to be a little extreme, I think ...) All kidding aside, Sopoforic, I' d like to offer a helpful suggestion or two. Those lists are certainly intimidating. I went through the first one only, and on a quick read-through hit just one item (Almost integer) that I've already thought of writing about. The idea I had there is that

${\frac {3^{12}}{2^{19}}}\approx 1.0136\,$

is the basis for Western music (well, the circle of fifths and Bach's well-tempered scale, at least), and that might provide an interesting tie-in to Ramanujan's continued fractions, which come a whole lot closer to being integers. Oh, yeah ... another interesting example is

$e^{3}\approx 20\quad \Longleftrightarrow \quad \ln 20\approx 3\,$

which, together with ln2 ≈ 0.7 is good enough to do a lot of mental arithmetic to one significant figure – three figures if you can think of ln2 ≈ 0.69315 (and this is the type of skill that is dying out all too quickly in the computer age, I think.) Anyway, the lists are terribly intimidating simply because they're so long. Can we maybe coordinate with Oleg somehow to split out the most notable missing articles so that new authors won't feel like they're undertaking a Sysiphean endeavor?

The other practical suggestion I'd make is to just start reading the articles on Wikipedia in areas that interest you. I started working on this stuff less than two months ago. I quickly found that there was practically nothing in Wikipedia about continued fractions with complex elements. Even the fairly prominent articles like complex analysis and complex plane seemed woefully inadequate. I've managed to put quite a bit into the article about the "complex plane", but complex analysis could still benefit from a whole lot more information of a general nature (such as an introduction to analytic continuation, and something about conformal mapping and its applications, etc). It would be good to prioritize the new article lists somehow, but even if that isn't done I bet you can find something good to write about if you just read some of the articles that are already here. DavidCBryant 19:32, 11 January 2007 (UTC)

I do read the articles quite a lot, but I only occasionally run across something I feel qualified enough to write about even with references. I suppose anyone (even I) could write the tiniest of stubs about most topics, but I'd hoped to be able to make a somewhat more substantial contribution. Thus, I was browsing through the missing articles list in search of something I understood.

I think it might be nice if these were categorized, as the requested articles are, since I've never even heard of many of these things. But, there are too many topics listed--we'd never get finished even categorizing them, I suspect. --Sopoforic 20:24, 11 January 2007 (UTC)

Even if they are categorized, it would take forever to create them all. But that's not even the purpose, really. As I view things, that list exists for the following reason: People bump into it, see a redlink, and say "gosh, I know about this". Then people end up writing one or more articles. So, that list is meant to "inspire" I would think, rather than be a to-do list.

In short, I'd suggest you take a look through the lists, see a topic which you feel is important, and which you know about, and write an article about it. On another day, you have nothing to do, then do the same thing. :) Oleg Alexandrov (talk) 04:33, 12 January 2007 (UTC)

Yeah, I get that. I just mean it'd be nice to have them categorized since, for example, I'm not very interested in analysis at all, but I'm pretty interested in combinatorics. So for me, I'd be more likely to bump into an article I could write/would want to write if they were by topic. But, like I said, the effort would surely be disproportionate to the benefit, and not in a good way. (Even the argument I gave seems falsified: I came across Kirkman's schoolgirl problem looking at the list, and it's very interesting indeed, so I made that article. Hopefully this will be a regular occurrence!) --Sopoforic 04:55, 12 January 2007 (UTC)

It may have been mentioned above, but in case it hasn't, the PlanetMath exchange project links are categorized. See Wikipedia:WikiProject_Mathematics/PlanetMath_Exchange if you wanna help out. Lunch 17:46, 12 January 2007 (UTC)

I wouldn't remove something merely because it does not seem notable to me, but maybe I would remove things that seem not notable to me. Michael Hardy 00:14, 13 January 2007 (UTC)

Florentin Smarandache on afd

Hello. I have put Florentin Smarandache on articles for deletion. See: Wikipedia:Articles for deletion/Florentin Smarandache. Please vote. Wile E. Heresiarch 06:18, 14 January 2007 (UTC)

Exponentiation

If anyone is interested, I could use a hand at exponentiation to get the content up to par and resist the efforts of a certain editor to add nonstandard definitions for complex exponentials, roots of unity, etc. CMummert · talk 15:04, 14 January 2007 (UTC)

Commercial / Business Math

I can't find a topic for an important branch of lower mathematics: that which is often called commercial math or business math. It is a practical subject, emphasizing simple arithmetic, percentages, and fractions, but also covering things such as banking transactions (writing checks, for example), purchase orders and invoices, consumer and business loans, etc. All of these things have a mathematical component, or at least a computational one, and they are very widely taught in commercial courses around the world. Does this subject have an article? If not, should it? What should it be called? —The preceding unsigned comment was added by Lou Sander (talk • contribs) 00:30, 14 January 2007 (UTC).

Oops! When I copied this over from elsewhere, I didn't want to include the out-of-date signature. Then I didn't put in a new one. (Another reason ALWAYS to preview.) Sorry. Lou Sander 00:33, 14 January 2007 (UTC)

There's a perfunctory stub on elementary mathematics. It isn't very good, even as stubs go (specifically, it focuses too much on a particular structure of education). Maybe you'd like to expand it, adding a section for business math? --Trovatore 00:49, 14 January 2007 (UTC)

Good idea. Better might be a separate article, though. Whichever way it goes, there needs to be a proper name for the subject. I think of it as "business math" or "commercial math," but those names might be old-fashioned, especially the second one. I teach a course in this stuff, and the famous textbook publisher calls it "college math," which I think is neither appropriate nor descriptive. What on earth do we call this important but pedestrian subject?? Lou Sander 01:08, 14 January 2007 (UTC)

Well, business math might be reasonable as a name for an article about a course (or a "topic" as our English friends, for some odd reason, call it). We have other articles on courses, such as pre-algebra. I guess the question is, if the article is not to be about a course, then what exactly is it about? I don't see that there's any other real unifying theme to the subject matter under discussion. --Trovatore 01:21, 14 January 2007 (UTC)

The unifying theme is its everyday usefulness in commerce. It is what most people think of when they think of "math." ("Most people" being the working classes, etc.) Lou Sander 05:15, 14 January 2007 (UTC)

I suppose that would fall under Elementary mathematics then, but why restrict it to business only? Elementary mathematics would have applications in all kinds of things; cooking, carpentry, sports, business, politics, etc. If you're interested in concentrating just on the business aspect however, you may want to check out the related topics under Business. It sounds like it would fit under the general topic of business as opposed to mathematics. I don't know if there's a talk page similar to this one in the Business subject though. capitalist 07:20, 14 January 2007 (UTC)

EDIT: I looked through the Mathematics Subject Classification briefly but couldn't really find a logical place for "business math". That's why I'm thinking it's more of a business subject than a mathematical one and would be better addressed by that community. capitalist 07:25, 14 January 2007 (UTC)

(Responding to Lou Sander) What I'm saying is that the difference between mathematics used in everyday commerce, and other mathematics, is not inherent to the subject matter; rather, what you seem to be discussing is one particular set of applications of techniques that have non-business applications as well. So you could have an article called applications of mathematics to business or some such, if that's the topic you're trying to get at. But those mathematical topics are not an inherently businessy sort of math, which is why I wouldn't be enthusiastic about lumping them into a business mathematics article. (Though, as I say, a business math article about the course taught under that name would be reasonable. --Trovatore 07:50, 14 January 2007 (UTC)

Update: Wow, business mathematics came up blue -- wasn't expecting that. It seems to be about the course. --Trovatore 07:52, 14 January 2007 (UTC)

Interesting (and thanks for finding it!). I thought I had looked for business mathematics, but I guess not. The present article doesn't now cover the material I'm referring to, but I'll give a shot at adding it. And it's more than just a course... it's what the vast majority of mankind (IMHO) thinks of as "math" -- arithmetic with commercial applications. Believe it or not, they don't even know what trigonometry is. Lou Sander 12:11, 14 January 2007 (UTC)

I added three short paragraphs to business mathematics, thereby (IMHO) plugging a minor hole in our coverage. Lou Sander 13:39, 14 January 2007 (UTC)

No objections to what's there currently. I just want to reiterate the point that we need to keep clear the distinction between "arithmetic with commercial applications" and "commercial applications of arithmetic". The former is not, IMO, an interesting way of categorizing anything; the latter might be. --Trovatore 02:27, 15 January 2007 (UTC)

Precision weighted

I came across this math stub and if anyone at the wikiproject would be interested in cleaning it up a bit. Or I can AFD it if it's not a real thing.Static Universe 19:30, 14 January 2007 (UTC)

It's not a cleanup, it's a complete rewrite, though there is little to rewrite. I speedied it for now as nonsense. Recreation should not be a problem.Circeus 20:13, 14 January 2007 (UTC)

Yeah, I was kind of understating it calling it "cleanup," but thank you. :) Static Universe 02:39, 15 January 2007 (UTC)

Mathematical analysis

The history in the article on mathematical analysis sounds suspect to me. At least it is very different then what I have been taught. I have tried bringing this up on the discussion page, but no were provided. Is anyone, or does anyone know a scholar in the history of mathematics who might take a look at it. I am reluctant to simply remove what is there because I myself can not say for wrong. Thenub314 20:58, 9 January 2007 (UTC)

To which portions of the History section are you referring, in particular? Are you suspicious of the claims made for the "Kerala School" in India? All of the Indian stuff? The "method of exhaustion" (Greece) is solid.

I agree that the bit about India is poorly written. Some of it doesn't even make sense. But I think the claims about actual mathematical discoveries in India are mostly right. The most controversial claim that has been made for the "Kerala School" is that Newton (and/or Leibniz) got his ideas from those guys. But this article doesn't appear to be making that claim. DavidCBryant 21:18, 9 January 2007 (UTC)

I may be correct, it just wasn't able to find any references that supported this point of view. But I should mention that my references are just the 2-3 math history books I own and the the MacTutor mathematics history site. But the fact the MacTutor history site did not claim so much was true, and gave a healthy list of references, togehter with the fact it never came up in my classes in the history of mathematics, made me suspect it. The things that I found particularly strange is the claims about derivatives and Rolle's theorem existing in 12th century india and term by term integration by 14th century. The information about infinite series, continued fraction and trig all seems to be spot on, and is quite amazing. But I just can't find refereed source that supports these claims. Thenub314 14:11, 16 January 2007 (UTC)

I'm trying to add references to the article when I can. If you have references and want to rewrite the paragraph about mathematics in India by all means go ahead and do so. I'm not certain that every bit of Indian historical information in the article is accurate ... I just said it's "mostly right". So if you think the bit about derivatives, and integration, is not quite accurate, blow it out of there. Or write me something on my talk page citing the references you've looked at, and I'll take a stab at that one paragraph. DavidCBryant 14:44, 16 January 2007 (UTC)

Computing Pi

This article seems problematic to me. It might be in violation of the rule against how-tos. AfD, or can it be improved, or merged somewhere? --Trovatore 06:25, 13 January 2007 (UTC)

I'm surprised to find that there isn't a natural merge target. Pi#Efficient methods seems to be the current home for such information; much of it should probably be merged away from that long main article. Melchoir 07:06, 13 January 2007 (UTC)

This topic is already well covered by our article on π, by our history of numerical approximations of π, and elsewhere. Since this stub is spotty, poorly written, and under the wrong title ("Pi" should not be capitalized), I'd say PROD, and AfD if necessary. (I see no point in a re-organization discussion unless a competent champion volunteers to do the work.) --KSmrq^T 07:23, 13 January 2007 (UTC)

Huh, I didn't notice it before, but that History of numerical approximations of π article has a lot of verbatim overlap with Pi#Efficient methods. That's a Bad Thing; surely someone can fix it? Melchoir 07:32, 13 January 2007 (UTC)

I agree that Computing Pi is not worth keeping on Wikipedia. I'm curious about the "rule against how-tos", though. I don't think I've run across that one yet ... would someone please point me to it? ("It's not that I want to break the rules," said Alice. "If only there weren't so many of them.") DavidCBryant 18:54, 13 January 2007 (UTC)

That would be WP:NOT#IINFO, under instruction manuals. Melchoir 19:18, 13 January 2007 (UTC)

A redirect to History of numerical approximations of π is a lot simpler than an AfD. By itself Methods for computing pi is a notable topic, and it is hard to maintain that the article is a how-to style manual.  --Lambiam^Talk 19:41, 13 January 2007 (UTC)

I think the redirect is a good idea. Oleg Alexandrov (talk) 19:56, 13 January 2007 (UTC)

Sure, I'd accept a redirect. And again, "someone can fix" anything on Wikipedia; I'm not keen on mythical beings.

The claim that any of these items constitutes a "how-to" manual and somehow breaks a "rule", like WP:NOT#IINFO, is debatable. Wikipedia has vast numbers of editors, and a correspondingly vast spread of opinions of what it is or should be. Take any opinion (including mine) as a thought to consider, not a commandment from God, unless it comes from Jimmy Wales. In the long run, common sense and consensus, trained by experience, are your best guide. In my opinion. ;-) --KSmrq^T 05:02, 14 January 2007 (UTC)

I don't think computing π needs to be a how-to. It could include how-to stuff but also theretical stuff about computation of π. For example, if there's a theorem that says no algorithm can comute the π to within ε faster than thus-and-so, it could be included.

I think it's a worthy topic, and although the present form of the article is clumsy, it could be brought up to reasonable standards.

I've fixed the title; it's now the Greek letter and not the upper-case "P". Michael Hardy 02:22, 15 January 2007 (UTC)

Are you suggesting we need both articles, History of numerical approximations of π – which has a section Development of efficient formulae – and Computing π? There is a huge overlap. I think one article covering the history as well as current efficient methods should be enough. Size is currently not an issue.  --Lambiam^Talk 11:22, 15 January 2007 (UTC)

Postscriptum. There is also Software for calculating π, Machin-like formula and List of formulae involving π#Efficient infinite series.  --Lambiam^Talk 11:34, 15 January 2007 (UTC)

The idea was not to make a how to(I'm sorry if it seems that way), it was to organise all the forumlas on the main Pi page . As it is, they are spread through-out the page. I find the "Calculating pi" section to be much cleaner now. The formulae section is large and alot to sift through right now. In my opinion the most important sections (Geometry, Physics,...) should be preserved and the rest (Analysis, Miscellaneous formulæ, ...) moved to appropriate pages (computing π, List_of_formulae_involving_π). Deathbob 02:15, 16 January 2007 (UTC)

Smarandache-Wellin number

I put Smarandache-Wellin number up for deletion; AfD discussion is here. —David Eppstein 20:59, 15 January 2007 (UTC)

Misner space

Could someone have a look at this? The article's derived from a popularization, and I'm not even sure this is an exact solution to GR or a piece of topology. Septentrionalis PMAnderson 23:11, 17 January 2007 (UTC)

I've trimmed it right down to something minimally verifiable: can someone who knows something about this expand it? -- The Anome 02:20, 18 January 2007 (UTC)

Is it really a good idea to take all that stuff out? It made some (little) sense before. Now it is a total mystery. JRSpriggs 08:18, 18 January 2007 (UTC)

Margin of error FAR

Margin of error has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. Kaldari 06:16, 18 January 2007 (UTC)

Odd bug in <math> processor.

Yesterday I was entering a formula that involved the expression z to the (2 to the n) power. I got a very odd result ... the <math> processor did not return an error (big red "failed to parse"), but the graphics engine that converts <math> to png images wouldn't work, or something, so that all I saw on a "show preview" was the raw TeX code, without the <math></math> tags around it. Oh – it also knocked the graphics interface out of commission entirely, not just on the line where I had the stacked superscripts, but throughout the rest of the page, as well. (I was using Firefox under Linux when this happened).

I finally figured out what the problem was by firing up my other browser, Konqueror, which rendered the other formulas OK, but failed on the one line that included z to the (2 to the n) power. That's why I suspect the graphics engine (it sort of gave up under Firefox, but Konqueror got a better result).

Anyway, I have a few questions. Is there a better place to report this problem? Some sort of technical support group, or something? And is there a central repository of information about bugs in wiki-TeX, where newcomers can learn about this sort of thing without having to hack through it on their own? Thanks! DavidCBryant 15:01, 18 January 2007 (UTC)

We have bugzilla for reporting bugs. They should be filed under 'mediawiki extensions.' --Sopoforic 17:06, 18 January 2007 (UTC)

The HTML "ALT" text for math images is the raw TeX code; you can look at it in Firefox by selecting "Properties" when right-clicking on a math image like this one $z^{2^{n}}\$. Maybe your browser just hadn't loaded the math PNGs and so was displaying the ALT text. Do you have a reproducible example of the bug? CMummert · talk 17:17, 18 January 2007 (UTC)

I can see the image just fine in your message, CMummert. I'll go back to the article I was working on and see if I can reproduce the problem. I don't generally right-click on images, but now that I've looked more closely I see that I've got an option "block images from wikimedia..." I suppose that I might have selected that option inadvertently. Maybe it was load-related ... as I mentioned, Konqueror got most of the images, just not the one image with $z^{2^{n}}$ in it. Sometimes when I run a search on Wikipedia it tells me to use Google or Yahoo instead. I guess that happens when the servers are under stress. Could there be something in the network OS that limits the generation of images when CPU cycles are getting scarce? That image generation process has got to be computationally expensive. Anyway, thanks for the feedback, both of you. DavidCBryant 19:13, 18 January 2007 (UTC)

I've been seeing a lot of random image loading failures lately, which especially impacts PNGs from <math> markup. These should (almost) all be cached, so I don't know where the failure is; I assume it is a server hiccup of some sort. --KSmrq^T 22:45, 18 January 2007 (UTC)

This is a known bug; refresh and it'll work fine. IIRC it is something to do with NFS and access times. — Preceding unsigned comment added by 58.163.151.30 (talk • contribs)

Opposite (mathematics)

The page Opposite (mathematics) might need some attention from any mathematicians. It was found in Special:Ancientpages, and could probably be turned into a redirect, or even deleted. --Montchav 16:53, 8 January 2007 (UTC)

I merged it into opposite. - grubber 05:52, 21 January 2007 (UTC)

A few polygons for deletion

I've nominated Hectagon, Pentacontagon, and Tetracontagon for deletion since Decemyriagon was deleted. You can find the discussion here. --Sopoforic 02:25, 22 January 2007 (UTC)

Merging Ramanujan summation?

It looks like Ramanujan summation and Ramanujan's sum are about the same, or very closely related, topics. Should they be merged? -- The Anome 12:55, 22 January 2007 (UTC)

I don't see the connection. The first article refers to a method of assigning a value to divergent series – that's probably something like Cesaro summation, although the article doesn't explain it very well. Is this one of those "Ramanujan mysteries", where people think anything he wrote down has to be important, but nobody else has figured it out yet?

The second article describes finite sums which cannot possibly diverge. DavidCBryant 14:35, 22 January 2007 (UTC)

I don't see how you could possibly merge them; the topics are not remotely similar. Michael Hardy 22:44, 23 January 2007 (UTC)

Triangle

I am having an argument with an anon at Triangle about what should be included in that article and what not. Comments would be welcome at Talk:Triangle#What should be included. Oleg Alexandrov (talk) 03:17, 24 January 2007 (UTC)

Set at AID

The article Set is up for nomination at the Article Improvement Drive. It's such a core topic in Mathematics that I'm surprised it's not at GA status already. CloudNine 14:46, 21 January 2007 (UTC)

Its nomination certainly has my support. Iotha 18:11, 24 January 2007 (UTC)

A couple of questions

I'm working on a couple of articles for mathematical problems, and I'd like some opinions on a couple of issues. First, I'm not quite sure what I should do when stating the problems. They're old enough that I can quote the original statement of the problem. Assuming that the original statement is clear enough, would it be a good idea to quote it directly, rather than trying to come up with my own wording? Second, regarding solutions: in Kirkman's schoolgirl problem, I've got a copy of an arrangement that solves the problem. Would the article benefit from listing this solution? It doesn't really add anything, from a mathematical standpoint (except proving that there is a solution, I guess), but perhaps a reader would be interested in it. I do intend to add more information to it once I get a few things via ILL, but should I add the solution in the meantime? --Sopoforic 23:37, 23 January 2007 (UTC)

It's a nice article, Sopoforic. I think examples and solutions are good to have. How long is the solution? If it's not too long, I'd add it. Oh – are you sure you want all those red links? I don't suppose there's any real rule about it, but I usually try to introduce no more than one red link in a new article, and then only if I intend to write the red-linked article fairly soon. DavidCBryant 23:59, 23 January 2007 (UTC)

IIRC, the style guide says to put redlinks whenever it'd be useful to have that information linked, and when it is probably possible to write an article on that topic. I'm thinking of writing up one or two of those, and it doesn't really hurt to leave them. But I should probably de-link the title of Ball's book in the refs.

The length of the solution? Well, an arrangement that solves it is just seven sets of 35 characters, so it's not much. The solutions that I have that explain how to arrive at this (or, better, proving how many different solutions are possible and things like that) are quite a bit longer. Ball's book gives a solution in a couple of pages which I can probably summarize and include.

I was really more concerned with the first part. I've written up a bit on Archimedes' cattle problem at User:Sopoforic/Sandbox, which I'm planning on copying into the article space once I've got a bit more added to it, but I'm not sure how I should state the problem. If you'd give your opinion on that, I'd be most grateful. --Sopoforic 01:14, 24 January 2007 (UTC)

A bit more info on this: I'm pretty sure I've found an English translation (out-of-copyright) of the 22 couplets that make up the statement of the cattle problem. It seems to me that it'd be nice to include this in the article, but what I've got written now is surely clearer in terms of the mathematical meaning of the problem. Further, a 44-line poem may make the article a bit long for small gain. Should it be added to the article? Or perhaps this is a time when wikisource should be used. I'm not really sure. Comments are welcome. --Sopoforic 01:53, 24 January 2007 (UTC)

I would add the solution to Kirkman's problem, as an aid to the reader; Archimedes' poem belongs in Wikisource (and a prose version might be better, unless the couplets are more accurate than usual for verse translations.) Septentrionalis PMAnderson 19:36, 24 January 2007 (UTC)

Giving credit for articles translated from the Wikipedia's of other languages

I translated Halley's method from French to English. My source was fr:Itération de Halley. So I just informally put a link to it in the article, saying "*[[:fr:Itération de Halley]], French original". The original author Lachaume (talk · contribs), asked me (at User talk:JRSpriggs#Halley's method) whether I should not be using a template. Is there a template for giving credit to sources on other Wikipedias? JRSpriggs 07:00, 25 January 2007 (UTC)

I don't think that there is such a template. Wikipedia:Translation/*/How-to has a template, but I think that it's meant for coordinating a translation effort, rather than giving credit. --Sopoforic 07:50, 25 January 2007 (UTC)

There are the templates Template:German, Template:Italian, Template:Polish, and so on, but it seems there is no template for French yet. Go figure. (NB: Template:French redirects to a navbox template.) See Category:Interwiki link templates or Category:Citation templates. Lunch 07:53, 25 January 2007 (UTC)

I didn't know of any template, but I think probably there should be a little more detail than just an interwiki link. At Prime minister of Italy I put a note in the References section pointing to the version I translated and stating the date it was retrieved. --Trovatore 07:54, 25 January 2007 (UTC)

Thanks. I will change it to follow your model, Trovatore. JRSpriggs 12:00, 25 January 2007 (UTC)

Articles listed at Articles for deletion

• List of formulae involving π (AfD discussion)
• List of physics formulae (AfD discussion) (see also Physics equations (AfD discussion))

Uncle G 12:02, 25 January 2007 (UTC)

Elementary mathematics

I think we really need some cleanup to be done on our articles on elementary mathematics. We put so much work into the articles on more obscure areas of mathematics, leaving our basic articles, the ones which are probably most viewed, neglected. Just by going to five random articles on elementary topics, I've basically either redone the opening paragraph or done serious work to all of them, as they were incomplete, incoherent, or misleading (see [1], [2], [3], [4], and [5]). —Mets501 (talk) 03:08, 25 January 2007 (UTC)

It's good that you are interested in editing these articles. For some reason, the more elementary articles tend to be the ones that lead to the most contentious editing. That may be why others stay away from them. CMummert · talk 03:25, 25 January 2007 (UTC)

I suspect it's due to the elementary articles being the most likely to be edited by a non-math person, or by a math person who has not yet gone into many of the advanced topics, which can lead to contentious editing (such as whether a trapezoid has only one set of parallel sides or at least one set. --Carl ^{(talk|contribs)} 14:47, 25 January 2007 (UTC)

Yes, most likely. They are also the most vandalized and edited, so it is harder to keep them stable. —Mets501 (talk) 14:57, 25 January 2007 (UTC)

Amen. I, too, had the experience of writing what I thought was a nice article on an introductory topic, which was promptly blanked by a clueless kid. I view the difficulty of editing and patrolling such articles as one of the more discouraging aspects of WP. This is why I've tried to follow the various proposals and efforts at defining "stable versions" and the accompanying editorial oversight boards.linas 05:50, 26 January 2007 (UTC)

I approach elementary articles timidly because they are difficult to write well. When I edit a more advanced article, I can use a sentence or two to orient the general reader and warn them off, then get down to business for the hard-core "mathematically sophisticated" reader. So-called "elementary topics" often aren't. What I mean is that they may first be met in early years, but a full treatment can draw on demanding foundations and lead to more sophisticated areas. Consider counting. This is something very young children learn and enjoy, but a full mathematical discussion should include the Peano axioms — a university-level topic, and might also consider the natural number object of category theory — a doctorate-level topic. It is already challenging to write well for young readers only, and considerably more difficult to write for graduate students at the same time!

And, as other have observed, since everyone "knows" (more correctly, thinks so!) about an "elementary" topic, everyone feels free to "improve" (actually, disrupt) the article. Primitive readers mess up the advanced delicacies, and advanced readers often lack sensitivity for young readers. Ah, the joys of Wikipedia! --KSmrq^T 05:59, 26 January 2007 (UTC)

series field in {{cite book}}

There is now a "series" field in the {{cite book}} template, as the following example illustrates. CMummert · talk 03:52, 26 January 2007 (UTC)

Mumford, David (1999). The Red Book of Varieties and Schemes. Lecture Notes in Mathematics 1358. Springer-Verlag. doi:10.1007/b62130. ISBN 354063293X.

{{cite book | last = Mumford | first = David | authorlink = David Mumford | title = The Red Book of Varieties and Schemes | publisher = [[Springer-Verlag]] | series = Lecture Notes in Mathematics 1358 | year = 1999 | doi = 10.1007/b62130 | isbn = 354063293X }}

This is good news. I cite a lot of books with {{cite conference}} but I think {{cite book}} would work for most of them and this gives a good reason to switch. Thanks! —David Eppstein 05:01, 26 January 2007 (UTC)

Notice by the way the very nice tool available at http://diberri.dyndns.org/wikipedia/templates/ which can generate book templates. Oleg Alexandrov (talk) 05:49, 26 January 2007 (UTC)

Zariski surfaces

Due to the recent banning of Dr. Piotr Blass, I have put his primary contribution to mathematics, the Zariski surface up for deletion as its sources are questionable, and the contributions made by Dr. Blass to the page also have some issues. Seeing as barely anyone knows what a Zariski surface is, I am bringing it to attention here to try and see what should be done.—Ryūlóng (竜龍) 01:51, 18 January 2007 (UTC)

ROFL we edit conflicted while I was composing my own version of this request. Yes, the creator and main contributor to this article has been sitebanned for persistent vanity and disruption. Dr. Blass claims to have named the concept of a Zariski surface and we non-mathematicians would would appreciate if specialists weighed in about whether this page meets site standards for retention. Respectfully, Durova^Charge 01:55, 18 January 2007 (UTC)

Piotr Blass does not appear to be the initial auther of the article, from the edit history. Richard Borcherds does so appear. Michael Hardy 01:05, 21 January 2007 (UTC)

It would be nonsense to delete it. At most it should be semi-protected. Charles Matthews 12:19, 22 January 2007 (UTC)

Piotr Blass is now on Wikipedia:Deletion review/Log/2007 January 24, with a new draft article. --Salix alba (talk) 23:25, 24 January 2007 (UTC)

AfD again. --Salix alba (talk) 08:36, 25 January 2007 (UTC)

Hi, I've started a basic fact dump for the "Ulam Quarterly" journal. As yet, I dont have an opinion on whether the journal would satisfy our notability criteria, but would appreciate any input by academics in the field. John Vandenberg 05:03, 27 January 2007 (UTC)

Something is odd with the categories system

I noticed something odd with the categories system. Take for example the article Maximum modulus principle. It is categorized in Category:Complex analysis as expected. However, if you actually visit that category, the article is just not there. Same for Argument principle, Antiderivative (complex analysis), etc., which are categorized in Category:Complex analysis but don't show up in the category itself. Anybody else noticing the same thing? Oleg Alexandrov (talk) 05:49, 26 January 2007 (UTC)

Seems to be some caching problem. I edited Maximum modulus principle, hacked on the cat, reverted myself, and now it shows up. linas 06:00, 26 January 2007 (UTC)

I've seen the same problem for the last week or so with Category:Graph products. It's only showing two articles, but there are several others with that category that are not shown. —David Eppstein 06:04, 26 January 2007 (UTC)

See also /Archive 21#A bug?. And I also had the problem with another file, but it went away when I moved an improperly located inter-wiki link down after the category. It seems to go away when you edit the file. JRSpriggs 07:25, 26 January 2007 (UTC)

It looks like saving the articles caused the category links to be updated. Saving the category did not seem to do the trick I looked at bugzilla briefly but didn't see anything. CMummert · talk 13:56, 26 January 2007 (UTC)

The articles that should be in Category:Graph products are: Cartesian product of graphs - Hedetniemi's conjecture - Lexicographic product of graphs - List of mathematics categories - Rooted product of graphs - Vizing's conjecture . Hmm. CMummert · talk 14:04, 26 January 2007 (UTC)

I reported it as a bug on bugzilla. CMummert · talk 14:10, 26 January 2007 (UTC)

Thanks! That's great! Oleg Alexandrov (talk) 03:32, 27 January 2007 (UTC)

The whole category system is vastly inferior in virtually all respects to the system of topics lists. Michael Hardy 21:07, 26 January 2007 (UTC)

I would disagree in the strongest terms. :) Categories are "bottom up" approaches, where each article is categorized independently of other articles, and a list of all categorized articles is automatically generated. "Bottom up" approaches work much better on Wikipedia than top-down approaches, like creating a list, where you need an expert to regularly and go through tons of articles and add list them in the appropriate list (that almost never happens, and this approach can't scale for millions of articles).

OK, lists and categories are actually complementary. Luckily we are not forced to choose between one or the other. Oleg Alexandrov (talk) 03:32, 27 January 2007 (UTC)

product rule

Maybe some of the really elementary articles should be on the watchlists of more mathematicians. Some idiot added to product rule a proposed "alternate proof". Those parts of the "alternate proof" that were valid were no different from the proof that was already there. But after saying f(x) = u(x)v(x) the "alternate proof" section said:

By hypothesis, $f'(x)=u(x)v'(x)+u'(x)v(x),\,$

and went on to rely substantially on that "hypothesis". I deleted it, and rebuked its author rather harshly---I imagine someone's going to accuse me of violating the "assume good faith" rule, but I think anyone who adds what purports to be a mathematical proof to an article should understand that which is secondary-school pupils are expected to learn about what proofs are. Michael Hardy 21:07, 26 January 2007 (UTC)

logarithm

In logarithm, I wrote:

The quantity log_b(x) is a function of both b and x, but the term "logarithmic function" in standard usage refers to log_b(x) as a function of x while b is fixed. Thus there is one logarithmic function for each value of the base b (which must be positive and must differ from 1).

Viewed in this way, the base-b logarithmic function is the inverse function of the base-b exponential function.

At talk:logarithm someone is disputing this and thinks my impression of what a logarithmic function is must have come from one book which I failed to identify. Perhaps others here can talk some sense into him (or into me, if need be). Michael Hardy 23:55, 26 January 2007 (UTC)

I am not disputing that statement. It is correct. Please see the Talk:Logarithm. —Mets501 (talk) 03:46, 27 January 2007 (UTC)

Most wanted redlinks

While updating User:Mathbot/List of mathematical redlinks, I made a list of redlinks which show up more than once in math articles. It is available at User:Mathbot/Most wanted redlinks (sorted by number of times each link occurs). Some of those might be worth filling in. Oleg Alexandrov (talk) 00:17, 28 January 2007 (UTC)

Nice. I was going to suggest something like this sometime :-) --C S (Talk) 01:20, 28 January 2007 (UTC)

BTW, I've had occasion to bump into editors who don't seem to realize red links are important. I left some comments to this effect at the talk page for Wikipedia: Red link. Perhaps somebody can help out with cleaning up that page. At the moment, some of the things are kind of confusing. For example, while a careful reading shows that red links are useful and should not be blindly removed, some people apparently read the part that explains that broken red links (ie. those leading to deleted pages or misspellings) should be removed and think that means all red links are broken.

Since WikiProject Mathematics uses red links in such a crucial systematic fashion, I think it would be good to modify that guideline (or whatever it is...) to mention this kind of use by WikiProjects. --C S (Talk) 01:25, 28 January 2007 (UTC)

Quadratic disambiguation

Formerly, Quadratic redirected to quadratic equation.

This was inappropriate in many of the contexts that linked to it. For example, Gyro monorail has "the stability quartic must be factorised into a pair of quadratic terms"; John Muth contains "Herb Simon had shown that with quadratic costs...", and algebraic function has "of a parabola, a quadratic algebraic function in x". The quadratic equation is not relevant to any of these.

I have made a disambiguation page at quadratic. But because there are many different, albeit related uses of "quadratic", it would probably be better if the links to the quadratic article were changed to link to more specific meanings: quadratic function, quadratic polynomial, or whatever.

-- Dominus 17:38, 28 January 2007 (UTC)

I've categorized the various kinds, as the list was a bit long. Also, I removed some of the entries, as some were redirects to things already in the list. Check it out and see if I have categorized them appropriately. - grubber 23:23, 28 January 2007 (UTC)

I just fixed a few of the links to quadratic ... it was fun. From the quadratic page I just hit "What links here" in the "toolbox" and started working through the list. Today I learned, for instance, that the Brits call vacuum tubes "valves". Fascinating! Oh – it just occurred to me. Isn't "quadratic disambiguation" when a dab page points to another dab page? Is there a rule against that?  ;^> DavidCBryant 13:01, 29 January 2007 (UTC)

Americans called them "valves" also, long ago. It's because they allow current to pass through in one direction, but not in the other. -- Dominus 21:03, 29 January 2007 (UTC)

That kind of work can be very satisfying sometimes. A while back I went around and disambiguated all the links to Red Hook. Most of them were actually referring to Red Hook, Brooklyn, but not all. I found out that H.P. Lovecraft lived in Red Hook, Brooklyn. What a surprise! -- Dominus 21:06, 29 January 2007 (UTC)

Is there a rule against a disambiguation page pointing to another disambiguation page? Not that I know of. I have seen it once or twice. Some words are used for so many different things that you need to have an overall disambiguation page with many entries and one of them points to another disambiguation page which separates the mathematical usages. JRSpriggs 08:07, 30 January 2007 (UTC)

This is odd. I was working through "What links here" when I ran across this dab page, which points to this dab page. It's self-referential (that is, quadratic itself is an example of second-order disambiguation). Did somebody do that on purpose?  ;^> DavidCBryant 11:26, 30 January 2007 (UTC)

Good job all, the nicest disambig page I've seen in a long while. --Salix alba (talk) 08:55, 30 January 2007 (UTC)

Feb 2007

Articles listed at Articles for deletion

• Complex conjugate root theorem (AfD discussion)

Uncle G 10:54, 29 January 2007 (UTC)

It wouldn't hurt to have some intelligent people comment on the above AfD, since the first several comments were written by silly gullible people. Michael Hardy 23:40, 29 January 2007 (UTC)

The AfD was closed with a resolution of keep. --KSmrq^T 20:21, 1 February 2007 (UTC)

Ancient pages

Out of curiosity, I made a version of Special:Ancientpages just for math articles: User:CMummert/Oldpages. It lists articles on Mathbot's list whose last edit was in 2005. There are no articles on Mathbot's list older than that (except for one redirect page, but I think I fixed that). CMummert · talk 04:53, 1 February 2007 (UTC)

List of mathematics articles are not Mathbot's pages. They were there long before mathbot or me were around. Oleg Alexandrov (talk) 05:13, 1 February 2007 (UTC)

Point taken. CMummert · talk 05:18, 1 February 2007 (UTC)

So the list shows that the vast majority of articles are edited quite a bit, although of course those edits could be trivial or vandalism. Interesting. Oleg Alexandrov (talk) 15:44, 1 February 2007 (UTC)

I was pleasantly surprised. The median age, by the way, is Dec. 21, 2006, and over 70% have been edited since Nov 1, 2006. CMummert · talk 16:49, 1 February 2007 (UTC)

Modularity theorem

For some time the article modularity theorem had the incorrect title Taniyama–Shimura theorem, a name invented by an editor who wrongly thought that was what the Taniyama-Shimura conjecture was called when it was proved, and never used by mathematicians. This has been fixed on the English wikipedia, but unfortunately this mistake was copied to wikipedias in many other languages. So the corresponding page in the following languages needs to be fixed: Català Deutsch Español Français Italiano עברית 日本語 Português Русский Suomi Tiếng Việt 中文 (There are links to the pages in these languages at modularity theorem.) R.e.b. 19:45, 1 February 2007 (UTC)

Infinite monkey theorem FAR

Infinite monkey theorem has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. LuciferMorgan 04:54, 2 February 2007 (UTC)

User:Farever, who apparently created his/her account for the sole purpose of nominating this article for FAR, has stated a kind of vendetta against the article's existence. This would appear to be a misuse of the FAR process. Is there a way it can be "speedy" closed? --C S (Talk) 06:13, 2 February 2007 (UTC)

Recreational mathematician article for deletion.

See Wikipedia:Articles for deletion/Ed Pegg, Jr.. Oleg Alexandrov (talk) 16:23, 31 January 2007 (UTC)

The AfD was closed with a resolution of keep. (After the stub was expanded there was no dissent.) --KSmrq^T 18:21, 4 February 2007 (UTC)

Nearly orphaned article

I found number spiral a complete orphan---no other pages linked to it at all. I did a few small copy-edits and put a link to it into another article, and added the "number theory" category. Perhpas others here can figure out which other articles should link to it or other categories it should be in. It would also benefit from an illustration and perhaps other additional work. Michael Hardy 23:11, 4 February 2007 (UTC)

Somebody linked Ulam spiral to it.--70.231.149.0 01:23, 5 February 2007 (UTC)

I believe number spiral fails the notability guideline's requirement of multiple independent nontrivial references, so I nominated it for deletion. Discuss at Wikipedia:Articles for deletion/Number spiral. -- Jitse Niesen (talk) 01:38, 5 February 2007 (UTC)

If it's not kept, I think it should be merged into Ulam spiral, perhaps with comments comparing and contrasting the two, and probably in terser and more efficient language than what is now in this article. Michael Hardy 02:06, 5 February 2007 (UTC)

Factorization

We really need to merge polynomial factorization and factorization; most of the article factorization is in fact on polynomial factorization, but it is treated more basically. Should we merge polynomial factorization into factorization, or merge most of the stuff in factorization on polynomial factorization into polynomial factorization? —Mets501 (talk) 04:11, 5 February 2007 (UTC)

Although polynomial factorization is certainly a kind of factorization, a merge in either direction would be unhelpful. Each topic has a great deal to be said about it, and neither should be burdened with the baggage of the other. If anything, factorization should be expanded in other ways. --KSmrq^T 05:23, 5 February 2007 (UTC)

Problem with HTML entities

Yesterday I was poking around through some W3C tables when I ran across a couple of HTML entities (&thetasym = #x03D1 and &weierp = #x2118) that were new to me. So I added them to the table of symbols in Fropuff's user space, and they showed up fine: ϑ and ℘.

Today the Weierstrass "p" symbol ℘ still works OK for me, but I get an ugly little hook for the "\vartheta" symbol that I should be able to produce by coding ϑ (this ought to look like ${\scriptstyle \vartheta }$ – yesterday it did, and today it doesn't). I figure it has to be in my browser somewhere. I'm running SuSE Linux 9.3, and I'm using Firefox 1.06 (yeah, I should upgrade Firefox, but it's kind of a pain to do, and I haven't gotten around to it). I did shut the browser down and restart it in the interim, so that's probably how I lost the glyph for ϑ, but I don't understand how that could happen. Oh – I also have my Wiki-preferences set to render all math expressions as PNG's.

Anyway, I'm curious if other people have any insight into this phenomenon. I also think I'm starting to understand the problem with in-line <math></math> expressions a little better. Please take a look at the following line in this message.

${\displaystyle \vartheta }\quad {\textstyle \vartheta }\quad {\scriptstyle \vartheta }\quad {\scriptscriptstyle \vartheta }\quad$ ϑ ${\displaystyle \wp }\quad {\textstyle \wp }\quad {\scriptstyle \wp }\quad {\scriptscriptstyle \wp }\quad$ ℘

Anyway, if everything were working right, there should be five copies of each of the symbols I'm talking about on the preceding line, in four or five different sizes. I only see three different sizes through my browser, but one of them (the {\scriptstyle} size) looks about right for rendering in-line symbols. Does it look that way to you? I'm especially curious what it looks like to Windows users. Should there be something more about different ways of rendering math symbols in the style manual for math articles? Thanks! DavidCBryant 17:36, 4 February 2007 (UTC)

Both symbols look ok to me, in Camino. They are bolder and more upright than the png math symbols, and each of the html symbols is larger than two of the corresponding png math symbols and smaller than the other two. —David Eppstein 17:56, 4 February 2007 (UTC)

All work for me. Although Fropuff's table includes TeX invocations, it's a tiny subset of all the symbols one might wish to use. Compare to my table, which includes HTML entity names (underlined) and MathML/Unicode names. --KSmrq^T 18:29, 4 February 2007 (UTC)

I am using the latest version of Firefox now; and the last of the five thetas looks very crudely drawn compared to the other four. JRSpriggs 06:23, 5 February 2007 (UTC)

Looking at them with my Internet Explorer, the last of the five in each group just look like rectangles. JRSpriggs 06:27, 5 February 2007 (UTC)

Thanks for the feedback. Are you using Windows XP, JR? "Crudely drawn" on the fifth one makes sense, since that's a font rendering, as compared to a graphic image (PNG) for the first four. I've done enough digging around on my own machine to convince myself that the problem is not really in my browser. It's buried deeper, in the font engine ("xft") for Linux. Oh, joy. Something else to learn about.  ;^>

Thanks for the big table, KSmrq. My system renders most of the symbols OK, up to about 0x'2900'. Past that I mostly get little square symbols that contain the four hex digits buried in the Unicode string. The "vartheta" string is anomalous (for me) because it's just 0x'03D1', a fairly low value, but it still renders badly. I guess I have to locate my LaTeX/Amsmath fonts and get them configured so that "xft" can find them. DavidCBryant 12:39, 5 February 2007 (UTC)

Squares appearing instead of the characters has nothing to do with which browser is being used - it is just a matter of whether an appropriate font including those unicode characters is installed. JPD (talk) 13:07, 5 February 2007 (UTC)

Not to put too fine a point on it, JPD, but it's not only a matter of installing the fonts. With most browsers, there's also a font configuration tool. So if you have two different fonts installed that can both render a particular Unicode glyph, your browser is going to select one of those ... and it may not be the one you'd rather see.

Anyway, I've got my ϑ problem straightened out now. I found fairly simple instructions on this web page, which may be of help to other Linux users. I installed about 50 new fonts (~ 7 MB) by following the instructions ... KSmrq's table looks better now, although I still have a significant hole between roughly 0x'2900' and 0x'02A00'. DavidCBryant 04:59, 6 February 2007 (UTC)

We are expecting the beta release of the STIX fonts "Real Soon Now", but meanwhile I find that one font, Code2000 fills almost every hole. --KSmrq^T 08:56, 6 February 2007 (UTC)

To DavidCBryant: I am using: Windows 2000, version 5.0 (Build 2195: Service Pack 4). I do not understand fonts, so all I can say about that is that I use: Verdana, style regular, size 10, script western. JRSpriggs 05:38, 6 February 2007 (UTC)

Hoaxing

One zero one (talk · contribs · deleted contribs · nuke contribs · logs · filter log · block user · block log) is editing math and physics related articles and (I think deliberately) introducing errors. They are not so easy to spot, see this edit for example. Such things are much more worrisome than plain vandalism. Something to watch for. Oleg Alexandrov (talk) 04:23, 5 February 2007 (UTC)

84.92.224.122 (talk · contribs · deleted contribs · filter log · WHOIS · RDNS · RBLs · http · block user · block log) did something similar at General relativity and elsewhere — changing the values of physical constants. JRSpriggs 05:46, 6 February 2007 (UTC)

Jacobi rotation

I think this should be merged with Givens rotation because it's the same. See e.g. Golub/van Loan "Matrix Computations" --Mathemaduenn 12:55, 7 February 2007 (UTC)

Yeah, they're the same thing. In the context of eigenvalue computations, they're usually known as Jacobi rotations, and they're otherwise usually known as Givens rotations. To quote Golub and van Loan, "Jacobi rotations are no different from Givens rotations, c.f. Section 5.1.8. We submit to the name change in this section [Jacobi methods for the Symmetric Eigenvalue Problem] to honor the inventor." You might add a {{merge}} tag to the Jacobi rotations article. Lunch 23:46, 7 February 2007 (UTC)

Perhaps you have not read the articles. Both are planar rotations (rotations of a two-dimensional linear subspace of a vector space), but the Givens rotation is a one-sided transform chosen to introduce a single off-diagonal zero in a matrix without regard to symmetry, while a Jacobi rotation is a similarity transform chosen to produce a pair of zeros in a symmetric matrix. The computations are completely different. Each article does refer to the other. Sometimes the names are used interchangeably, but the distinction is well worth keeping. I believe if you actually read the excellent Golub and Van Loan book, which is cited, you will find no contradiction.

One possible source of confusion is that when we have a real symmetric matrix like

$M={\begin{bmatrix}2.6&0.2&-0.7&-2.4\\0.2&-4.4&1.9&2.2\\-0.7&1.9&4.2&-2.5\\-2.4&2.2&-2.5&-1.7\end{bmatrix}},$

then a Givens rotation of the last two rows that zeros the −2.4 entry in the last row, when applied from the left, will (by symmetry) act in transposed form from the right to zero the −2.4 entry in the last column.

$Q={\begin{bmatrix}1&0&0&0\\0&0&-0.28&0.96\\0&0&-0.96&-0.28\end{bmatrix}}$

$QM={\begin{bmatrix}2.6&0.2&-0.7&-2.4\\0.2&-4.4&1.9&2.2\\2.5&1.58&-3.576&-0.932\\0&-2.44&-3.332&2.876\end{bmatrix}}$

$QMQ^{T}={\begin{bmatrix}2.6&0.2&2.5&0\\0.2&-4.4&1.58&-2.44\\2.5&1.58&0.10656&3.69392\\0&-2.44&3.69392&2.39344\end{bmatrix}}$

We can systematically work in this fashion to reduce M to tridiagonal form, but we cannot diagonalize it. If we zero an element on the subdiagonal with a Givens rotation, the zero is immediately destroyed when we complete the similarity transform. So we must choose our rotation as described in the Jacobi rotation article to actually get zeros. Of course, a side-effect of that is to create a "bulge", destroying our tridiagonalization.

${\begin{aligned}M&{}={\begin{bmatrix}2.6&0.2&0&0\\0.2&-4.4&1.9&0\\0&1.9&4.2&-1.2\\0&0&-1.2&2.4\end{bmatrix}}\\Q&{}={\begin{bmatrix}1&0&0&0\\0&1&0&0\\0&0&0.8944272&-0.4472136\\0&0&0.4472136&0.8944272\end{bmatrix}}\\QMQ^{T}&{}={\begin{bmatrix}2.6&0.2&0&0\\0.2&-4.4&1.69941&0.84971\\0&1.69941&4.8&0\\0&0.84971&0&1.8\end{bmatrix}}\\\end{aligned}}$

We are not surprised; otherwise we could find roots of polynomials of arbitrary degree using radicals, which is impossible. --KSmrq^T 03:05, 8 February 2007 (UTC)

The transformation both use is the same, but you're right, they're applied for different effects. In context, Givens rotations are only applied one-sided whereas the Jacobi rotations are applied as a two-sided similarity transform. Sorry, I guess a merge isn't in order. (But I do wish you wouldn't just up and delete my comments.) Lunch 03:52, 8 February 2007 (UTC)

I have not knowingly deleted your comments, and would only delete any comments in extreme circumstances, such as severe spam or vandalism. However, this bug has bitten repeatedly, so I'm (sadly) getting used to the complaint. I never get the slightest warning in advance, only irate responses on the (so far) unpredictable occasions when it occurs. (Sigh.) Maybe one day the software will get fixed, or I will find a reliable workaround. Meanwhile, please, restore anything you wish that mysteriously disappeared. --KSmrq^T 06:57, 8 February 2007 (UTC)

(No worries. It happens.) Lunch 18:53, 8 February 2007 (UTC)

Have you tried not hitting the "back" button after the preview, as you say you often do? I'd be curious if that solves the problem. There's not really a need to do that anyway. --C S (Talk) 10:06, 8 February 2007 (UTC)

I don't think that this is the common use of the term "Jacobi-Rotation". That's all. Maybe my first comment was to short. So a book source should be added. The content of Jacobi-Rotation can also be used to improve Jacobi eigenvalue algorithm. But it's only a suggestion. --Mathemaduenn 13:53, 8 February 2007 (UTC)

Do you mean this isn't a common use of the term "Jacobi rotation"? In that case, isn't Golub and van Loan good enough to establish that usage?

Or do you mean this isn't the common use of the term "Jacobi rotation"? If so, what else have you seen this term used for?

Thanks, Lunch 18:53, 8 February 2007 (UTC)

The use is "It is the same as Givens Rotation." and how KSmrq said these names are used interchangably. Also Golub van Loan defines Givens Rotations and uses Jacobi Rotation in the same manner. It's a Rotation in the plane spanned by e_k and e_l. --Mathemaduenn 09:02, 9 February 2007 (UTC)

Various issues

A few things I'd like opinions on:

First: are we (we, anybody) using the {{Maths rating}} template? I come across articles all the time without it on them (like Polygon, for example, which I guess is top-class or high-class importance, or whatever the word is we use). I could add this to articles (talk pages, rather) when I notice it's missing, but I don't want to do it if it'd just be a waste of time.

Second: should we have a category for math problems? I don't mean like 'integrate x^2', but things like Archimedes' cattle problem, Kirkman's schoolgirl problem, Doubling the cube, etc.

Third and fourth: It seems that Mathbot hasn't removed bluelinks from the math articles listed at WP:MST since august. It's not a big deal, but should I just do it by hand? Also, there are some things listed that I don't quite know what to do with: take, for example, Mud cracks (listed on Wikipedia:Missing_science_topics/Maths18. MathWorld says that cracks in mud tend to cross each other at right angles--the Mud Cracks article on mathworld redirects to Right Angle. Mathworld cites some sources to support this, too. Should wikipedia mention that in Angle? Or maybe in Mud? (Imagine: a project mathematics banner on Mud). It seems like it'd be hard to justify putting it in there. On the other hand, it's vaguely interesting (for some definition of interesting) and apparently verifiable. What should be done?

Suggestions, as always, will be appreciated. --Sopoforic 01:41, 8 February 2007 (UTC)

Second: I don't see why not. Article topics should be categorized by what they are in addition to the field of science into which they fall, and not just in math. Melchoir 00:23, 9 February 2007 (UTC)

Re the rating template: I can imagine them being used to prioritize effort, but I don't know that anyone does use them in that fashion. One other use is to show our recognition of well written articles or improvements to articles by giving them better quality ratings. I have at least added a few more of these templates (and filled out the fields in some uncategorized ones) since seeing your note here. —David Eppstein 02:53, 9 February 2007 (UTC)

Replies:

1. According to Wikipedia:WikiProject_Mathematics/Wikipedia_1.0 anybody can grade articles with the {{maths rating}} template as they see fit. I'm sure the guys working on it would appreciate the help.
2. I think something like Category:Famous mathematics problems would be a fine category.
3. You have to ask User:Oleg Alexandrov about this one. He runs mathbot.
4. If anywhere I think it should be mentioned in the Mud article. That article wouldn't warrant a math category because of it though. In short mud cracks shouldn't be listed at WP:MST.

-- Fropuff 04:56, 9 February 2007 (UTC)

All right, I'll put the rating template on articles when I notice them. Regarding the category, probably just Category:Mathematics problems or Category:Problems or something would be enough--if they weren't famous (or at least notable), we wouldn't have articles for them. I'll leave a note for User:Oleg Alexandrov if he doesn't chime in before I get a chance. And, finally, I'll see about adding a note to Mud (once I decide whether it's worth adding, anyway). Thanks for the replies, everyone. --Sopoforic 17:19, 9 February 2007 (UTC)

Template:Hilbert's problems

What do we think about: Template:Hilbert's problems. Given that we have Category:Hilbert's problems, do we think the template is useful? Paul August ☎ 19:27, 8 February 2007 (UTC)

Some people prefer template navigation. But if we keep it, we should do one of two things:

• mask with Roman (or arabic) numerals ([[Hilbert's tenth problem|X]],
• replace it with {{otherarticles}} (or {{otherarticles-alph}}) Septentrionalis PMAnderson 19:47, 8 February 2007 (UTC)

The ancient debate of navational boxes vs. categories. Navigational boxes do not add any information, but as PMAnderson notes some people find them user friendlier (less mouseclicks.) Now if all those boxes where properly marked up being navigational boxes, people who dislike them could hide them. (P.S. Maybe there should a way to automatically generate those boxes through the articles included in a certain category.) —Ruud 20:03, 8 February 2007 (UTC)

There is a class="messagebox standard-talk collapsible collapsed" command which gives a template the little show/hide box. See {{WikiProjectBanners}}. But is that enough to fix this? Septentrionalis PMAnderson 00:12, 9 February 2007 (UTC)

I agree with Septentrionalis. I would prefer an other article template that simply pointed to the main Hilbert problems article. These problems are so diverse and their numbers are so uninformative about the actual content of the articles that I don't see the navbox as useful. —David Eppstein 23:03, 8 February 2007 (UTC)

Agree. If I saw that box at the bottom of the page, I wouldn't know what to do with it. I know what the problems are (generally), but I wouldn't know them by number. There's no real benefit in providing easy navigation if the user can't tell where they're going. The table present in Hilbert's problems is much better for navigation. A notice like {{otherarticles}} should be fine (though it ought to point to Hilbert's problems, not the category, in my opinion). --Sopoforic 02:51, 9 February 2007 (UTC)

It does both; it has two arguments; see Template talk:otherarticles Septentrionalis PMAnderson 06:01, 9 February 2007 (UTC)

The new version of Template:Hilbert's problems is much more palatable. Paul August ☎ 16:22, 9 February 2007 (UTC)

Yeah, but I still question whether it adds any value. The only use cases I can think of are: you accidentally stumble upon an article for one of Hilbert's problems, and realize that you want to look at problem #17, but don't feel like clicking the link to Hilbert's problems; or, you want to navigate through all of them to read about them, but don't want to have an extra window/tab open to click them from Hilbert's problems. The first is unlikely; the second is possible, but I don't know whether it's going to be important enough to justify an otherwise-meaningless template. On the other hand, space at the bottom of the article is cheap: this isn't doing much harm, anyway. --Sopoforic 17:15, 9 February 2007 (UTC)

Possible uses would be quickly opening each article in a tab or reading the introduction of all the Hilbert problems by using popups. Some people find this useful, some don't. —Ruud 19:57, 9 February 2007 (UTC)

If you're opening them in tabs or reading with popups, you can do it from Hilbert's problems just as easily. But, like I said, it isn't really doing any harm, either. --Sopoforic 23:50, 10 February 2007 (UTC)

What can be done about "Exponential smoothing"?

Exponential smoothing has been around for a long time. Although it appears to be on a legitimate topic, it is one of the most poorly written articles. So badly written in fact, that the difficulty of fixing it probably deters people from even trying. As EconStat (talk · contribs) said, "I feel really sorry to see poor work like this on Wiki.". It is too far out of my field for me to fix it. If no statistician is willing to fix it, perhaps we should put it up for deletion. What do you think? JRSpriggs 06:46, 5 February 2007 (UTC)

Why not just rewrite it as a short stub, since the current content is quite odd. Eventually someone will decide to expand it from there. Deletion is usually reserved for topics that don't deserve an article even if it was written well; there is no deletion criteria for articles with bad writing. CMummert · talk 14:03, 5 February 2007 (UTC)

I'm willing to take a stab at a complete rewrite, since I have extensive experience with time series. I notice that moving average already exists as a financial topic. Although financial applications of time series attract a great deal of attention today, the statistical techniques for improving "signal to noise ratio" are more widely applicable than that. For instance, someone with limited daily temperature data for a particular location might base his "forecasts" for this year's daily highs and lows on a moving average of actual temperature data from the past two or three years. DavidCBryant 16:52, 5 February 2007 (UTC)

I've done some (very badly needed!) cleanup. More is needed. Michael Hardy 21:53, 5 February 2007 (UTC)

Thanks, Michael. I hope you and the others can stand to wade through it. JRSpriggs 05:54, 6 February 2007 (UTC)

OK, I just dumped a complete rewrite in there. It's not comprehensive, but at least it's a reasonable start. Please take a look and polish it up a bit. Thanks! DavidCBryant 00:50, 10 February 2007 (UTC)

Thanks, David. It looks much better. Now that you have fixed it up, I expect more people will jump in with changes. JRSpriggs 06:32, 10 February 2007 (UTC)

I put a comment on the weighting on the talk page Talk:Exponential smoothing#Problems with weighting. JRSpriggs 03:51, 12 February 2007 (UTC)

Many thanks to Michael and David for cleaning it up. --A bit iffy 07:53, 12 February 2007 (UTC)

question about definitions of objects

Some time ago I was looking at free algebra's for a paper I was doing in Universal Algebra and I looked at the wp page on the subject. The definition was a sort of "abstract algebraic" or "ring theory" definition, and it got me to wondering about definitions of mathematical objects on WP. A free algebra could be defined in the language of UA, of category theory, or probably in other ways. How does one know which way to go for a WP page on a mathematical object? If someone wanted, they could easily go to dozens of articles and add in UA or category theory or whatever definitions of everything from logic operators to who knows. I was thinking of adding this question to the Math MoS, but I figured it would be ok to add it here. I think that the answer should be incorporated into the MMos, or somewhere in a policy guideline.

To answer my own question a bit, in many cases the most naive definition is best, who wants to mess with this stuff in an arithmetic page. On the other hand there are some cases where almost all of the research in a subject is done by logicians or computer scientists or whatever, so the definition they use is best. But, this is a type of WP imperialism, as many pages are defined with the CS way of looking at it due to the high number of editors with CS backgrounds, frustrating other potential users. Sometimes the subject can be safely split into how different fields look at it (such as Combinatorial game theory and Game theory), which can also help. Smmurphy^(Talk) 02:15, 13 February 2007 (UTC)

It depends on the level of the expected reader of the article. The article on natural numbers should be much more elementary than the article on groupoids. But there is no limitaton on the space that we can use to describe a topic, so any relevant and notable definition can be included, at least in a subsection. For example, Peano axioms gives a categorical definition as a subsection. CMummert · talk 02:30, 13 February 2007 (UTC)

I am having this daydream of future WP wars where category theorists approach every math article and add a category theory definition (or move that definition to the top), while putting new research into a new category, "math which is not yet sophisticated enough to warrant a category theory approach." Computer scientists counter marking articles as "math which doesn't and will never have real world applications," and universal algebraists add a reference to Burris & Sankappanavar to dozens of articles. Smmurphy^(Talk) 02:46, 13 February 2007 (UTC)

Recently translated article, needs expertise

Could someone have a look at Gauss-Lucas theorem. It needs to be put into context and made understandable to a general audience. − Twas Now ( talk • contribs • e-mail ) 05:04, 13 February 2007 (UTC)

categories for deleteion

Category:Claude Shannon, Category:Norbert Wiener are up for deletion at WP:CFD 132.205.44.134 00:45, 15 February 2007 (UTC)

Some missing topics

I have a short list of missing mathematics topics. I have tried to find all relevant links to similar articles but I would appreciate if someone could have a look at it. Thank you. - Skysmith 13:44, 16 February 2007 (UTC)

There is a list of requested articles at Wikipedia:Requested articles/Mathematics. You should consider adding these to that list. CMummert · talk 19:25, 17 February 2007 (UTC)

New math articles

Just as a reminder to perhaps newer people, there are two pages where one can see what is going on with the math articles. First, Jitse's very versatile Wikipedia:WikiProject Mathematics/Current activity, and then my own User:Mathbot/Changes to mathlists which justs lists articles added and removed from math lists.

There is a lot going on in math on Wikipedia, with at least five (or more like ten) articles created daily (my unscientific guess is that we are creating articles at a much faster rate than either PlanetMath or MathWorld). There is a lot of work however in making sure that those articles have proper style, are correct, notable, and mathematical. So, if you have time, taking a look on those pages every now and then could be a good thing. Cheers, Oleg Alexandrov (talk) 22:28, 10 February 2007 (UTC)

I looked through several new articles this morning and I see two reasons why we may be getting so many of them.

• People who speak English as a second language want to write articles about mathematicians with whom they're familiar. I noticed several articles about Russian mathematicians which (to judge by a conspicuous lack of the word "the", and by the names of the contributors) were probably written by Russian authors.
• People who don't understand mathematics well enough to look for a topic related to the word they're curious about. For instance, there was a new article for "leptokurtotic", plus an older stub article for "leptokurtosis". We already had redirects for leptokurtic and platykurtic in Wikipedia, and an excellent discussion of fourth moments at kurtosis. So I was able to clean out a couple of useless articles by coding some new redirect pages (for leptokurtotic and leptokurtosis and platykurtotic). Those words look like poor English usage to me, but they're present on the web, so people look them up on Wikipedia. And if the words aren't here … Voila! A new article is born. DavidCBryant 17:07, 11 February 2007 (UTC)

That's why we need more people to look over recent additions. Bad articles are caught best when caught early. :) Oleg Alexandrov (talk) 23:48, 11 February 2007 (UTC)

I keep on noticing new patterns as I work through the lists of new articles. Here are a few I've been seeing recently.

• Ideas that are "out there", but that accrete templates/stub notices/category tags without being deleted. Probability control is a "good" example. I count 28 words in the original article, and 107 words in the moss this rolling stone has gathered during its brief career.
• Articles that discuss mathematical concepts from a non-mathematical point of view. Here are two (Self-referencing doomsday argument rebuttal and Negative probability) that I found particularly amusing, in case anyone else wants to have a look. I took the "probability" tags off both of these so they can go swim around as philosophy and/or "pseudophysics".
• Redirect pages that have category tags stuck on them. The categorization crew is having a field day.
• Real solid new math articles. Supersingular K3 surface is a good example. Thankfully there are quite a few of these. DavidCBryant 14:15, 17 February 2007 (UTC)

Yep, a good chunk of those articles should either not exist as written or are not properly categorized so they are often not math. Oleg Alexandrov (talk) 16:27, 17 February 2007 (UTC)

Here's another odd situation. 56 (number) has existed since 13 December, 2003. Because of a recent unfortunate edit, its entire revision history has been disconnected. That revision history is now associated with another article, 56 (game). The article about the card game was actually created on 16 February, 2007, but it now has 3+ years of history associated with it, even though it's really only 2 days old. How am I supposed to straighten something like that out? I guess it's not a huge deal, but it doesn't seem right, somehow, that an article should be divorced from its edit history. DavidCBryant 14:34, 18 February 2007 (UTC)

The story started with an anon blanking 56 (number). Then in a few days somebody else saw the blank page and created an article about the game 56 (note that the IP of the guy who blanked, 71.233.129.128, is very similar to the IP of the guy who created the game, 71.250.232.151, although that's probably a coincidence).

I moved back 56 (game) to 56 (number) and reverted to the pre-blank version. The game itself doesn't seem notable enough to have its article. Oleg Alexandrov (talk) 16:13, 18 February 2007 (UTC)

About images

I've already done some hunting through Help:Images and other uploaded files and some other associated pages, and I haven't found an answer yet, so I'm asking a question here. Is there a recommended maximum size for image files embedded in a Wikipedia article? If not, should there be?

Here's why I'm asking. I was reviewing the list of new math articles when I ran across Shallow water equations. It's an interesting article. And it has a very nice animated GIF embedded in it, which illustrates waves in a bathtub evolving over a period of time. The only problem is that the graphics file (Image:Shallow_water_waves.gif) is roughly 7 Mb in size. On my machine the animation takes about 30 seconds to run. So I'd need a data transfer rate of ~250 Kb per second to view this animation in real time, and I don't have that kind of a connection.

I'm just wondering if there's some sort of convention for a really big graphics file like this one. I think it's a nice animation, especially for people who have high-speed internet connections. But roughly half of all the internet users are still using dial-up, AFAIK. Wouldn't it be nice to link to an animation file like this one as a separate article, with a caption describing the file you're about to download? DavidCBryant 17:31, 14 February 2007 (UTC)

You might grab a single frame from the animation to use as a still image in the article. You could then put in a wikilink to the animation with a note about its size. As a further enhancement, if you're super-duper motivated, you could recompress the animated GIF into Ogg format.

Nice addition to the article, BTW. Lunch 19:50, 14 February 2007 (UTC)

That animation could certainly be clipped to the first 2 (maybe 3) splashes without losing any content. Tesseran 05:47, 17 February 2007 (UTC)

I think you should insist that images which load slowly be put in a separate file with a link to it. That way, if you know your connection is slow you can avoid clicking on it and just read the text of the article. But if your connection is fast or you are willing to wait, you can click on the link and see the image. JRSpriggs 07:45, 17 February 2007 (UTC)

Boy's surface kills my browser due to huge animations even with a high-bandwidth connection. I think the first animation on the page adds a lot to the understandability of the surface, but it should probably be significantly reduced in size, and one of the editors of that page seems to feel that if one animation is good more must be better. —David Eppstein 08:06, 17 February 2007 (UTC)

Same thing here David, it killed my browser too. I also have a high-bandwidth connection. Definitely needs to be reduced in size.--Jersey Devil 08:21, 17 February 2007 (UTC)

Thanks for all the responses. Apparently there is no convention about big images. Or at least, nobody has heard of it. I guess I'll try asking in a couple of other fora. Oh – I should clear up some apparent misconceptions. Lunch, I didn't make up any graphics files. The shallow waves animation is from Dan Copsey. I was wrong when I said half of all internet users are on dial-up – I checked some statistics on that, and it's more like one-fourth (23% in the U.S., currently). Interestingly, the total size of the graphics files I received on the Boy's surface article is just 2.0 Mb, or about 29% of the size of the splashing water animation. But the biggest picture there (1.2Mb) is served at the top of the article. At least Dan Copsey had the good sense to put his little movie at the bottom, so a user doesn't necessarily notice that the big grapic is loading until he scrolls down the page. DavidCBryant 12:29, 17 February 2007 (UTC)

I've just done a heavy prune of Boy's surface I've cut out two of the visulisations and two sections devoted to visulisation of the surface. --Salix alba (talk) 18:39, 18 February 2007 (UTC)

Apologies?

Saying that the Project consists of "only suggestions" sounds apologetic. I think that starting a Wikiproject with an apology or disclaimer is probably a bad idea. The overall tone of the project does not sound heavy-handed. Have others reacted badly to the existence of this project? Many of the other WikiProejcts do not start their page with such caution.

Also, there was briefly an attempt to provide some kind of realistic status. It read:

Perhaps the greatest sign of distress in this WikiProejct at the start of 2007 is that of the five articles that are both FA and Top importance, three of them are biographies (See also the chart in Wikipedia:WikiProject Mathematics/Wikipedia 1.0). The other two articles are Polar coordinate system and Game theory, the latter of which contains not a single equation or diagram of a spatial nature. Surely, more of the non-biography articles in Category:Top-importance mathematics articles can be brought to FA status this year. Let us aim for the goal that some of those new (or restored) FA's contain equations.

This assessment seems fair and points in an interesting direction. Should it be put back? For perspective, you might want to familiarize yourself with WP:100K.--199.33.32.40 22:08, 4 February 2007 (UTC)

I strongly support a non-prescriptive approach to Wikipedia; and one of the things that make this project worthwhile is that it begins with one. See WP:PRO.

My opinion of WP:FA is far lower: it will promote essentially worthless articles like Daniel Webster, which is written out of Henry Cabot Lodge's artificial and dated exercise in biography. FA cannot exercise better judgment than its members', and its members have none. The current review of infinite monkey theorem alone will show this. Septentrionalis PMAnderson 22:57, 4 February 2007 (UTC)

I do not mean to be contentious, but even if the FA process sux, it is all we got. I would like to roast alive the monkey in IMT as badly as you. In my imagination, I can smell that acrid burning hair even as we...but I digress. To start off with such weak-willed verbiage as we do betrays a lack direction in our WikiProject. Wouldn't it be more motivating to just have a rousing "Let us get some FA-quality content secured" and try to ignore the gauntlet of inline-obsessed editors we have to go through to get there? We can make it if we just do the content-building and the inline refs, and respond to the feedback, no matter how unfamiliar or uncomfortable the demanding FA reviewer is with, say, first-semester calculus. We should encourage a positive, constructive attitude and, you know, pretend like the FA process does not sux. It is just a matter of determination, judgement and productive focus on our part.--199.33.32.40 00:35, 5 February 2007 (UTC)

Before you start changing the WikiProject page to state your desires for what the WikiProject should focus on, you should discuss it first on this talk page. After all, it doesn't seem like you've even participated enough in this WikiProject to get a sense of what the community thinks. Also, is there a reason that you apparently created a new account (User:Farever) and stopped using it? Keeping track of the different IPs is kind of annoying.

Speaking for myself, non-prescriptiveness is a good thing. If it distinguishes us from other WikiProjects, that'll all for the good. I believe the main purpose of this WikiProject is to improve mathematical coverage on Wikipedia. We all have differing ideas of what this means. Some may argue that this entails more FA mathematics articles, while others disagree. I personally wonder if the our time is most effectively utilized tweaking articles to make it through the FA process. There are bigger issues, e.g. fixing the elementary mathematics articles. --C S (Talk) 04:22, 5 February 2007 (UTC)

The anon does raise some good points about lack of FA quality articles for our most important articles. I second the comments about getting a login name, you will be taken more seriously with one. Over the last year I think there has been improvment in the general quality of our more important articles. The situation looks better when you consider our A-Class articles, better still when GA and B+ class articles are taken into account.

Personally I'm not too fussed about FA-class articles, it takes a lot of work to acheive and maintain and their are some systematic dificulties we face trying to gain that status: anything sufficiently advanced is likely to fail as the reviewers will find it hard; continued debates over citations; brilliant prose is not something mathematicians are trained in. I'd much rather see our top and high importance article gain B+ or higher quality so we have a good all round coverage.

One thing I've been thinking about is having some sort of formal process for an article to obtain A-class status. We could set our own criteria which reflects the needs of mathematical articles and a brief review process. --Salix alba (talk) 09:46, 5 February 2007 (UTC)

I agree that developing our own criteria for A-class articles would be a good idea. A recent discussion in Wikipedia: namespace has highlighted the fact that the vast majority of rated articles in the whole encyclopedia are rated Stub, Start, or B, while very few are rated B+ or A. This is certainly the case with the math project. The criteria don't require that A-class articles are perfect, only that they are very good, and each project is free to develop customized criteria for A-class articles (although the only one I could easily find is the Military History project). CMummert · talk 01:35, 21 February 2007 (UTC)

Cleanup main project page

I would like to mark Wikipedia:WikiProject_Mathematics/Motivation and Wikipedia:WikiProject_Mathematics/Proofs as historical and direct additional conversation from them to this page instead. I looked at them today and realized that they are still gaining new comments, even though the main project page seems to describe them as historical discusions. Any objections?

Also, the 2006 update is beginning to look a little old in Feb. 2007. I would like to add a 2007 update. What are the main issues that require attention this year? There have been several comments in recent weeks about improving articles on elementary subjects, so that might be a candidate for one. CMummert · talk 13:53, 5 February 2007 (UTC)

I think a better idea is to move the historical discussion to an archive page, e.g. .../Proofs/archive1. Keep some of the more recent comments (from the last several months). That way when the conversation starts getting long and involved it will be localized in one obvious spot, as I predict there will be long gaps in the discussion; otherwise, Werdnabot will shelve parts of it in different spots. It should also decrease repetitionin discussion. --C S (Talk) 14:34, 5 February 2007 (UTC)

The look of the project page could be improved. Wikipedia:WikiProject Molecular and Cellular Biology has a fairly clean look to it, and a minimum of fancy graphics, which should please Oleg. Work on elementary, top and high class articles are my suggestions for attention. Also WP:MATHCOTW seems to have very little activity of late, the last article chosen was in mid November. --Salix alba (talk) 14:25, 5 February 2007 (UTC)

When did Oleg get the reputation for not liking fancy graphics? :-) I would miss the 2002 retro look, but the page is starting to get unwieldy. --C S (Talk) 14:49, 5 February 2007 (UTC)

I guess Salix alba means this. I actually kept the graphics the anon put in, but reverted anon's modifications to the text part. That because I'd rather have one of us look through the page and decide how to reorder things than allow an anon coming out of the blue to do things. And no, I have nothing against graphics, as long the pretty pictures help in usability rather than just distract. Oleg Alexandrov (talk) 16:44, 5 February 2007 (UTC)

I cleaned up the page some. I like to put links at the side so that it is easier to start reading at the top. I don't dislike images per se but I don't see how the images in the newly-added nav box actually helped the page any. And they were too big. CMummert · talk 02:27, 7 February 2007 (UTC)

The nav box is great. The box currently includes links to the discussion pages on proofs and motivations. So it seems like you agree with my prior comments. Should we archive those pages (to subpages) and create clean versions, which can hopefully be managed in a more organized way? At this point, I also recommend everyone watchlist those pages, since it appears that discussion on those issues may be centered there. --C S (Talk) 13:25, 7 February 2007 (UTC)

I don't feel strongly one way or another about keeping the other two talk pages. There have been no comments on Motivation since 2005, so my instinct is to mark it as historic and list in with the talk archives of this page. The Proofs talk page should definitely be archived and cleaned up. CMummert · talk 13:56, 7 February 2007 (UTC)

The proofs and motivations subpages should really be moved into the Wikipedia talk namespace since they are, in fact, discussion pages. Whether we should mark them as historical or keep them open is debatable. Should these pages ever produce some sort of recommendations/guidelines we can put those in the Wikipedia namespace. -- Fropuff 23:32, 7 February 2007 (UTC)

There is some discussion for having discussion pages in the Wikipedia namespace: the village pump and reference desk. But if you want to move them I doubt anyone will revert it. CMummert · talk 04:38, 8 February 2007 (UTC)

I've just redone the project page in a two column layout[6]. The Nav box by CMummert caused a few layout problems so I've cut and pasted it for now and and hacked it a bit to make it work. Feel free to revert. --Salix alba (talk) 21:18, 7 February 2007 (UTC)

I like the new layout :-) Interesting how the (superb) animation of tesseract has become the unofficial logo ... only (minor) problem is that the sidebar is bigger than the main content, and will (hopefully) get bigger as more maths articles become FAs and GAs. Hmmm.... I seem to be putting (occasional) words in brackets a lot.Tompw (talk) 00:12, 8 February 2007 (UTC)

Perhaps, the graded articles material (good/featured articles) should go on a subpage. That way, future growth won't overwhelm the main project page. Also, if we are going to have a logo for this project (official or otherwise) perhaps we should vote on one. The tesseract animation is superb indeed, but I find animated gifs somewhat distracting. -- Fropuff 02:10, 8 February 2007 (UTC)

The new layout is problematic of narrow screens. The actual text content is in a narrow column about 2 inches wide on the left while the sidebar on the right is about 4 inches wide. I'll tweak it some.

Is there a non-animated image that could be used instead of the animated one? I'm not so sure that an image belongs here, instead of on the Portal. In my mind, the function of the project page is to gather together resources that help editors. CMummert · talk 03:19, 8 February 2007 (UTC)

I tried, but I couldn't get the two-column layout to work with a narrow screen. The image here (warning: advertising) is a screenshot that demonstrates the problem in firefox; it's worse in opera. So I added the new content (image, MCOTW, graded articles table) to the old version and reverted. If there really is huge demand for a two-column layout I won't fight against it, but I think that as long as the rest of WP is in single-column format our page should be as well. I'm sure I'm not the only person with a narrow screen. CMummert · talk 04:23, 8 February 2007 (UTC)

Erdős number categories up for deletion yet again

Wikipedia:Categories_for_discussion/Log/2007_February_9#Category:Erd.C5.91s_number_1

The discussion has been going on since Feb.9, so speak quickly or you may not get a chance to speak at all. —David Eppstein 07:23, 19 February 2007 (UTC)

Update: discussion was closed early today with a result of no consensus. The closing admin doesn't seem to have paid attention to our requests for more time so that WPM members could respond, but we did get quite a few responses in the short time available. —David Eppstein 23:41, 20 February 2007 (UTC)

We don't want to give the appearance of group-think by mobbing these discussions; there were probably enough comments by mathematics editors at the end. A more useful way to convince people of the notability might be to add additional published references to the Erdos number article. I would guess that some of the papers named there as "External links" were actually published. Once Erdos numbers are established as clearly notable, the categories are harder to argue against. Personally, I am neutral about the categories - individual articles are free to state the Erdos number of mathematicians whether or not they are categorized as such. CMummert · talk 00:07, 21 February 2007 (UTC)

I've refrained from these discussions, because I don't have a leaning either way. One thing that disturbs me is that it seems arbitrary to have a category for say, Erdos number 6 (which I think was actually created in between these CFD debates). Is there, for example, a cutoff typically used by social network researchers? --C S (Talk) 00:41, 21 February 2007 (UTC)

Six degrees of separation says that everyone is connected by six steps, indeed we find that the modal Erdos number is 5 and virtually all mathematicians (97%-ish) will have EN of 7 or less.[7] (P.S. debate now closed as no consensus) --Salix alba (talk) 07:56, 21 February 2007 (UTC)

Having co-authored a paper with someone is a much closer relationship than just knowing him/her. JRSpriggs 08:33, 21 February 2007 (UTC)

Closer still is co-authoring a book. As with buying a certain brand of automobile, a revealing question is, "Would you do it again?". The Mathematics Genealogy Project is also fascinating. But most of one's professional life comes after graduate school, and it is hard to document influences and connections. A broad web of co-author connections tells more than the Erdős number, and even that cannot show how much a researcher was influenced by reading Lagrange or Atiyah or Grothendieck.

We can admit, without prejudice, that the Erdős number is partly of interest as entertainment, perhaps a step up from "What's purple and commutes?" (An abelian grape.) Beyond that, it also serves to remind us to collaborate, whether as co-authors or merely as colleagues. Such encouragement is especially important for mathematicians, because by inclination and by necessity, we often work in solitude.

How do we explain that to the rest of the world? Wikipedia devotes more pages to sports and films and games and other forms of entertainment than it does to mathematics, so it would be churlish to deny us our fun. And like Playboy's other content (short stories, interviews), the Erdős number has social value. --KSmrq^T 11:00, 21 February 2007 (UTC)

At the risk of being obvious, one's Erdős number is a status symbol, an indication of how well-connected one is within the mathematical community. JRSpriggs 11:50, 21 February 2007 (UTC)

Numerical digit

I just rewrote this article; please visit, improve the article, and offer comments. It's a vital article, so I think we should work to improve it to at least good article standard. --N Shar 20:25, 20 February 2007 (UTC)

If you are interested in getting some sort of assessment for the article, I would recommend first improving it, then putting it up for peer review, and finally nominating it for Featured Article status. But you should be aware that the criteria for featured articles may differ from the criteria that we ordinarily use to assess mathematical writing. CMummert · talk 20:43, 20 February 2007 (UTC)

Actually, I'm just looking for reassurance that I didn't completely ruin the article. --N Shar 20:59, 20 February 2007 (UTC)

The new article is a significant improvement over the previous version. CMummert · talk 22:40, 20 February 2007 (UTC)

Thanks. I'm still working on it; maybe I will nominate for peer review/GA after it gets some references. --N Shar 22:45, 20 February 2007 (UTC)

special characters

The articles Naive set theory and Subset use special math characters that show up as squares in IE 7. There are probably other articles like that. Can someone substitute the TeX math characters? Bubba73 (talk), 05:09, 15 February 2007 (UTC)

Or, you could join the civilized world and install a font or two. The STIX Fonts project will be releasing theirs soon, and Code2000 has long been available. This is no different than if you were reading an article involving Chinese or Arabic; you'd need fonts for those notations as well. --KSmrq^T 06:39, 15 February 2007 (UTC)

It works fine for me with IE 6, so it may be an issue of some font not being installed. Looking at Wikipedia:Mathematical symbols, can you identify which characters don't display properly?  --Lambiam^Talk 06:35, 15 February 2007 (UTC)

A large number of those don't display correctly, e.g. the last four of Analysis, the last six of Arrows, and the last four of Logic. None of Sets are correct except the next to last one. Bubba73 (talk), 20:03, 15 February 2007 (UTC)

With Lucida Unicide, all of those display except the fifth and sixth delimiters. Bubba73 (talk), 02:13, 16 February 2007 (UTC)

Or switch to Mozilla Firefox as I suggested at Naive set theory. JRSpriggs 09:04, 15 February 2007 (UTC)

Sometimes I use Firefox, and they are OK there. But I mainly use IE 7. Many other people use that too. Bubba73 (talk), 20:04, 15 February 2007 (UTC)

No, it's a matter of an appropriate font being installed. Unless it is, it won't matter which browser you use. JPD (talk) 10:24, 15 February 2007 (UTC)

I did some digging around, and found this very helpful web page. Should we try to get some links to this worked into a Wikipedia article about MathML / Unicode / UTF-8 somewhere? DavidCBryant 16:43, 15 February 2007 (UTC)

I changed my main browser font to Lucida Sans Unicode, and now they display correctly. Other people have had the same problem. I don't know if this is the best solution, but it fixes that. My thanks to the users who helped. Bubba73 (talk), 20:43, 15 February 2007 (UTC)

Lucida Sans Unicode can fill many character gaps if you have it. Unfortunately, Microsoft restricts distribution, and Wikipedia is viewed with many browsers and operating systems. If you want to see how good your character coverage is now, I keep a page with hundreds (!) of mathematics characters, here. --KSmrq^T 01:02, 16 February 2007 (UTC)

I have Lucida Sans Unicode, it must have come with my system. It fills in many of the gaps in math symbols. Farther down the page, though, most are still missing. And using that font changes the font of a lot of other websites. Bubba73 (talk), 19:17, 16 February 2007 (UTC)

Ok this is the first place I've seen a contemporary discussion about the display problems that I've been

long plagued by in WikiPedia. I've tried to find and implement and analyze solutions, but I'm at a loss, so I thought that by sharing in some detail my own experiences / results / efforts that I can help others understand, solve, or become aware of the difficulties. I appreciate the efforts of those who've taken the time to author what appear to be many fine technical pages on WikiPedia, I simply wish that many of them were usefully accessible to me. I have to believe that my IT/PC/Browser setup is representative of or better than that of most casual Wikipedia users, so I imagine that if I (and others here) are having such difficulties that the problem must be widespread and that the solution(s) are poorly known. Yet given the substantial quantity of well authored and similarly encoded technical pages on WikiPedia, it stands to reason that the authors must be aware of the appropriate guidelines, tools, techniques, and encoding / authoring techniques to create their pages, view them correctly, and have some 'quality assurance' expectation that most of their audience should be able to view their works with reasonable success and facility. However, if that's so, I've certainly missed finding "the instructions" as to how to repeat their successes! I've been impatiently waiting for the STIX fonts and FireFox 2.x for nearly a year hoping that maybe it was just a local font and rendering engine deficiency that I could clear up with those tools, but alas it's appearing unlikely to me that it's "simply" explicable and soluble by those two issues. I'm hoping that someone who does have mathematical (et.al.) symbol display mostly or wholly working with their browser can speak up and help answer what configuration(s) are beneficial to achieve that result. Though I've often seen FireFox lauded for superior MathML et. al. display versus IE6, I'm presently (and miserably) having the opposite experience. Using a "full" default install of WinXP, fully updated recent versions of FireFox 2.0.0.1 and MS IE 6.0.x, I'm unable to correctly see a great number of Wikipedia's mathematical symbols under FireFox and I'm missing a lesser but significant number of them on MSIE 6. Following the tips of users' comments here and elsewhere I've tried both FF and IE, I've installed the recommended TeX, MTExtra, Mathematica, MathML, et. al. fonts, I've experimented with changing my default encoding's font and size to several various choices including the installed Lucida Sans Unicode, et. al. I've enabled JavaScript, Cookies, Style sheets, and web site overrides of my chosen default fonts. I've reloaded the pages containing inappropriately rendered characters many times to judge whether anything I've done has made an improvement. ...For example, with this representative page:

• http://en.wikipedia.org/wiki/Quaternions

I notice that under MSIE, even before installing non-default fonts, automatically loaded many PNG images to display graphic representations of symbols / equations, and by so doing that it got many of them correctly displayed. Whereas on the same system under FireFox, even after correctly installing numerous additional fonts, most missing characters are still displaying TeX-like escape codes in plainly visible "text code" and the rendering is neither invoking "png image loading" to display graphic representations of the symbols/equations (like MSIE is doing), nor is FireFox apparently able to or trying to render the symbols / codes via any of the installed MathMl / Unicode fonts et. al. ...For another example:

• http://en.wikipedia.org/wiki/Wikipedia:Mathematical_symbols

In FireFox, the above page correctly shows a couple of dozen of the symbols; most of leftmost ones are all OK; the bottom rows as well as most of the symbols on the right sides of all rows do not display correctly; instead I see what looks like character entity references as one would type them "in code". In MSIE, the page display is just about equally broken as it is under Firefox. It's showing a combination of empty box characters and textual character entity reference codes instead of most of the characters on the right and bottom side of that page. ...I've followed the instructions / suggestions at the below couple of sites to install new Windows fonts and have verified that they're installed and recognized / available to the browser(s) and system in general:

• http://www.mozilla.org/projects/mathml/fonts/
• http://web.mit.edu/is/topics/webpublishing/mathml/

...I'm a developer myself and am not unfamiliar with XML, MathML, fonts, UNICODE, HTML, TeX, et. al., but despite several hours worth of googling, experimentation, and looking for Wikipedia pages on tips for using its Mathematical Notations with browsers, I have yet to find a solution or even consistent diagnosis for this seemingly fundamental and oft encountered problem. Even in the context of this Talk Page there's contradictory information about whether it's the fault of the browser, missing fonts, user configurations of browser fonts, et. al. If it were just a browser issue, I would expect that in either MSIE6 or FFox2 I'd have "mostly successful" experiences; I do not. If it was a missing font issue, I'd expect that having installed all the platform default as well as dozens of commended added technical / symbol / mathematical fonts would have mostly solved the problem; it has not. If it was mostly a local problem, I'd expect that most Wikipedia pages would look uniformly good / bad and act consistently; they do not; the following page displays much more successfully than the second following one:

• http://en.wikipedia.org/wiki/Quaternions
• http://en.wikipedia.org/wiki/Wikipedia:Mathematical_symbols

If it was "mostly just my errant setup" I wouldn't expect to see evidences of other users reporting similar problems, so many contradictory hypotheses about the problems, and I'd have expected to find some kind of FAQ / guide suggesting "the standard configurations" that'd be working for most people who had followed suit. Another example:

• http://en.wikipedia.org/wiki/Spinor

...looks mostly bad and unrendered in FireFox 2, whereas on the same system, IE6 renders it mostly fine though it's clearly resorting to WikiPedia server-side provided png graphic renderings of the equations / symbols instead of using any local font. Another example, this looks to be an excellent and useful test matrix of characters / symbols:

• http://en.wikipedia.org/wiki/User:KSmrq/Chars

On both MSIE6 and FireFox2 (cum MANY additionally installed technical font sets) the page's table is mostly absent correctly rendered symbols. A great number of them (but still perhaps well less than half) are properly rendered in FireFox. A significantly lesser number of them correctly render in MSIE6; mainly the first 22 rows from the top are mostly OK in MSIE, whereas most of the rest of the table is not rendered. If it was a local font issue, I'd expect relatively uniform "pass/fail" between the two simultaneously active browsers. Clearly from the quaternion WikiPedia page there must be, at least in THAT case, a different stylesheet or something Wikipedia is using to tell MSIE to graphically load many of the page's equations, whereas doing something different and more unsuccessful for FireFox. Does ANYONE have these pages mostly / fully working, and, if so, what's the secret, please?!

• http://en.wikipedia.org/wiki/User:KSmrq/Chars
• http://en.wikipedia.org/wiki/Wikipedia:Mathematical_symbols
• http://en.wikipedia.org/wiki/Spinor
• http://en.wikipedia.org/wiki/Phasor_%28electronics%29
• http://en.wikipedia.org/wiki/Naive_set_theory
• http://en.wikipedia.org/wiki/Partial_differential
• http://en.wikipedia.org/wiki/Partial_differential_equation
• http://en.wikipedia.org/wiki/Jacobian
• http://en.wikipedia.org/wiki/Maxwells_equations

Overall I'd say that most work very poorly in FireFox, and the ones that work 'well' in MSIE are exclusively ones where, somehow, a graphical versus textual representation is provided 'server side' via Style Sheet or some other mechanism to cause MSIE to not even try to display most of the symbols / equations via local font or rendering technologies. Obviously that .png bitmap graphic approach leaves a lot to be desired (scalability, searchability, accessability, et. al.), but at least it's a visual "on screen" step forward wrt. total gibberish. It must be a choice that's not consistently or fully implemented server side, though, since many of the pages don't try to do that in MSIE and in such cases the result is no better than in FireFox. I haven't extensively experimented with this issue in LINUX, though I've encountered similar problems sufficiently often with FireFox/LINUX to suggest to me that there's nothing uniquely beneficial about LINUX's browser / fonts that makes it work much better than I've experienced under MS Windows. If anything LINUX tends to lack some of the more 'common' TrueType / UNICODE fonts that are 'often' available on MS Windows platforms, so OS platform doesn't seem to be the essential problem. —The preceding unsigned comment was added by 216.99.216.242 (talk) 09:10, 22 February 2007 (UTC).

(You were use *foo* for emphasis, rather than the wiki ''foo'', which conflicted with the wiki interpretation of a line beginning with "*" as a bullet point. Fixed.)

I have seen no feedback suggesting your ordeal is typical. Perhaps that means widespread satisfaction, or perhaps it means most give up in quiet despair. Given the amount of effort you have invested, we can certainly invest some ourselves to help you achieve success. I suggest we first concentrate on using Windows XP, Firefox 2.0, and one or two pages. To begin, please install a copy of BabelMap. We will especially use its "Tools>Font Analysis Utility..." (shortcut:F7) menu option, to show which installed fonts cover a chosen Unicode block.

While you do that, I'll give some relevant background. Mathematics display within Wikipedia is far from ideal, mixing several different techniques. Complicated equations imitate TeX:

<math>\int_a^b f(x)\, dx = g(x) + C </math>

→

$\int _{a}^{b}f(x)\,dx=g(x)+C$

These go through a process that produces a PNG image. So as not to overload the servers, the images are cached. Lately I've found that images of all sorts, not just equations, often fail to load. Since I haven't changed anything on my end since six months ago when this rarely happened, I assume Wikipedia is having technical difficulties. Standard browser behavior for a missing image is to display the alt content, which in this case will be the TeX input for the equation. Simple equations may (partly depending on user preference) generate HTML instead of an image.

<math>g'(x) = f(x)</math>

→

$g'(x)=f(x)$

This should always work. Special characters and more complicated equations force the PNG.

<math>g'(x) = f(x) \,\!</math>

→

$g'(x)=f(x)\,\!$

<math>g'(x) = \tfrac12 f(x)</math>

→

$g'(x)={\tfrac {1}{2}}f(x)$

At present Wikipedia has no MathML support, so our best alternative is Unicode and markup. We can illustrate with a line from Wikipedia:Mathematical symbols:

'''Logic:''' {{unicode|&not; &and; &or; &exist; &forall;}} &amp;not; &amp;and; &amp;or; &amp;exist; &amp;forall;

→

Logic: ¬ ∧ ∨ ∃ ∀ &not; &and; &or; &exist; &forall;

On this line, the characters displayed on the left are produced by the text shown on the right. (Notice that on the right the ampersand is entered as &amp;, so the ampersand character is displayed, rather than used as an escape character.)

Only a small number of characters have HTML names like this, but any Unicode character can be produced in one of two ways. The first is as a numeric entity, like &#x22A2;. The second takes advantage of WikiMedia's UTF-8 support, allowing any character to appear verbatim, like ⊢. This particular character, RightTee, is covered by Lucida Sans Unicode, so if you have that font installed and if your browser is configured to use it, in principal it should display without trouble. However, it is not covered by fonts like Arial or Times New Roman, so some users may see a "missing character" glyph, typically an empty box or question mark. The fonts in my table are basically ordered by Unicode code point (numeric value), which means the further down you go the more exotic the character, and the less likely it will be covered. For example, Unicode includes a dedicated symbol, Cross, for the cross product, ⨯, code point U+2A2F [VECTOR OR CROSS PRODUCT]. BabelMap tells me it is covered by Code2000, but by no other font I have installed, including Lucida Sans Unicode. (This is why I so firmly recommend Code2000!)

Maybe this information will help a little. --KSmrq^T 16:12, 22 February 2007 (UTC)

Another AfD

The article Checking if a coin is fair is up for deletion. People who read this page might want to take a look at it. DavidCBryant 14:59, 15 February 2007 (UTC)

The decision was to keep the article. --KSmrq^T 15:19, 24 February 2007 (UTC)

More deletions

Felix A. Keller and Keller's Expression

Keller keeps adding himself and his unimportant and obvious expression to the page about e. He has done this at least four times since 2004. Now he has promoted himself and his expression to a pair of articles.

See Wikipedia:Articles_for_deletion/Felix A. Keller to discuss.

-- Dominus 16:51, 15 February 2007 (UTC)

Obviously, given that the links have turned red, the result was delete both. --KSmrq^T 09:59, 22 February 2007 (UTC)

Importance

Some articles about individual mathematicians who were important in the development of math are rated as top importance, e.g. Leonard Euler and Gottfried Liebniz, or mid importance, e.g. al-Khwarizmi. But shouldn't all of those articles be rated as low importance, because who developed the concepts is not relevant to math, it is historical trivia, wikiproject mathematics should really only concerned with articles that focus on technical aspects of mathematics. Prb4 19:55, 15 February 2007 (UTC)

So, you're saying that these articles you mentioned above might be top-importance in some biography project, but not in a Mathematics project? I think I see where you're coming from. I guess it all kind of depends on what this Wikiproject really encompasses. –King Bee ^{(T • C)} 20:02, 15 February 2007 (UTC)

The history of mathematics is an important component of mathematics. In many cases, the history says a lot about the mathematics itself. (The obvious example would be the Newton/Leibniz development of calculus.) Maybe you're saying that the history is fine, but the biography is less relevant to the math itself. Like the previous poster, I see what you're getting at, but I disagree. We should include key biographies in any list of important articles. VectorPosse 20:23, 15 February 2007 (UTC)

I think User:Pbr4 is referring to the "importance" field of the rating box appearing on some talk pages. This doesn't refer to the importance of the article to this project; it refers to the importance of including the article on a yet-to-be-made CD or DVD version of the encyclopedia. Presumably there would not be enough space for everything, so the importance field is supposed to help choose which articles to include. Interpreted this way, it makes sense for articles about Leibniz and Euler to be high importance — they are of high importance for making the DVD coverage similar to other encyclopedias. It is a historical coincidence that biographies of mathematicians are covered by the mathematics wikiproject. CMummert · talk 20:31, 15 February 2007 (UTC)

Historical coincidence? Well, I wouldn't quite put it like that. A lot of wikiproject members just find working on bios of mathematicians interesting, perhaps of relevance to the actual mathematics. I would say that editing mathematics and mathematical bios are often so complementary, e.g. the actual researching involved can be linked, that it makes sense things should be like this. --C S (Talk) 22:28, 15 February 2007 (UTC)

Technically importance does relate to importances within the specific project, and not for the CD or biographies as a whole. It is allowable to have difference imporance rating for different projects. coin flipping is one example with two different importances and theres others within the cross over with cyptography.

It is important to remember that we are writing an encyclopedia not a maths text book so historical information is a vital component. Actually I think haveing historical coverage is one of our unique aspects as history so so often neglected in mathematical texts. I learned must of my group theory not knowing in which century it was developed! Historical info can add context to the maths and helps show the development of the ideas.

We did spend some time trying to assess importance of the top 100 or so mathematicians and in some respect these are some sort of comparision with other mathematicains. Flawed yes, but a rough measure. There is also the field argument in the rating template and bios all have field=biography. At some point in the future, when the number of graded articles has grown, it may be possible to sperate out the mathematicians so we can have one list for strict maths articles and another for mathematicians. --Salix alba (talk) 00:26, 16 February 2007 (UTC)

I find this talk about 'historical trivia' to be actually offensive. What is more, the proposition that mathematics articles should be only about mathematics, narrowly defined, makes no sense in terms of the needs of the general reader; which is where WP aims, in principle. Further, I know from past comments that mathematicians themselves can find historical context helpful. Charles Matthews 19:31, 18 February 2007 (UTC)

I agree, although I would add that writing accurately about the history of mathematics is extraordinarily difficult compared to writing about mathematics. One reason is that writing about technical mathematics is more or less standardized, whereas I don't think that's true for history of mathematics.--CSTAR 19:54, 18 February 2007 (UTC)

I did some digging around to learn more about the Wikipedia:Version 1.0 Editorial Team (these are the guys trying to organize the contents of the CD version to which CMummert referred, above). You can see the list of "important" mathematicians the team has identified on this page. The list of "important" topics in mathematics is right here. DavidCBryant 16:17, 21 February 2007 (UTC)

A question about categories

I was reviewing Complementary sequences and noticed that the only math-related tag on the article was for the category "Elementary mathematics" (which seems strange, since Golay codes aren't all that elementary). Anyway, that got me curious about other topics associated with error correcting codes. I couldn't find any corresponding topics in the list of mathematics categories. So then I looked at several of the articles in list of algebraic coding theory topics and found that some of these are "math" articles (because they carry category tags like "finite fields") and some of them aren't (because they carry category tags like "error detection and correction").

So now I have a question. What's the preferred procedure in a situation like this? Is it OK to add another category to the list of mathematics categories? What if that category is likely to drag in a bunch of articles that aren't really math articles? Would it be better to add some more specific tag (like "finite fields") to some of the articles (in, say, "error detection and correction") that seem entirely mathematical? Frankly, I'm a little bit confused by the existing hodge-podge of "categories" on Wikipedia! DavidCBryant 17:58, 18 February 2007 (UTC)

There is no good answer to your question. Whether a given article belongs to a given category can be a subjective question, and whether a given article is a math article is also a subjective question.

I created the list of mathematics categories and I have mathbot add articles from those categories to list of mathematics articles so that we have a way of noticing and listing math articles. I try to be rather conservative about what categories to include in there, and categories which contain a lot of non-math articles usually don't make it in. I don't know if that's a good idea in the long run. Outside review of list of mathematics categories is very welcome.

If you feel strongly that a certain article should be in the list of mathematics articles you can either add it to a "mathematical" category as "defined" in the list of mathematics categories (then the bot will automatically list that article), or you could add that article directly to the list of mathematics articles (the bot does not remove articles from there, even if they are not in math categories, the bot just adds articles and removes redirects and redlinks). Oleg Alexandrov (talk) 18:12, 18 February 2007 (UTC)

OK, Oleg – thanks for the information. I ran across two categories that aren't on the control list for your 'bot, but that appear to have a great number of math articles in them. You might want to add "Category:Coding theory" and/or "Category:Information theory" to the list of mathematics categories. If you decide not to do that, then I'll try to make time to add the math articles in those two categories onto the list of mathematics articles. I looked through both categories for a little while, and found some articles that are already on the "math article" list, and others that are clearly math-oriented, but not on the list yet. DavidCBryant 00:43, 19 February 2007 (UTC)

I added Category:Coding theory to math categories. I don't feel comfortable adding Category:Information theory however. It has too much stuff which is not really math. And the category is generic enough that people may occasionally put odd stuff in it, and there's going to be more work to keep strange things from popping into the list of mathematics categories. Perhaps some of those articles could be categorized into "more mathematical" categories? Oleg Alexandrov (talk) 03:01, 20 February 2007 (UTC)

I've just done some cleanup on complementary sequences. Using an asterisk for ordinary multiplication, as if we were restricted to plain ASCII, is uncouth; we're not primitive troglodytes. Also, notice this difference:

N-1

N − 1

Michael Hardy 21:13, 19 February 2007 (UTC)

Thank you for working on it, Michael. My wife would not necessarily confirm your hypothesis: that I'm an actual example of Homo sapiens, and not a more primitive species of primate.  ;^> Sorry I didn't catch all the poorly coded stuff in complementary sequence the first time through, but after putting in about 75 or 80 of those non-breaking spaces (to make the big long vectors look better) I just got tired. There's only so much of that kind of stuff I can take at one sitting. DavidCBryant 23:47, 19 February 2007 (UTC)

No David, you ain't a troglodyte. Michael is a homo sapiens too, by the way, just one of grumpy subspecies. :) Oleg Alexandrov (talk) 03:01, 20 February 2007 (UTC)

The real troglodytes — Pan troglodytes. JRSpriggs 05:44, 20 February 2007 (UTC)

Oleg is mistaken as to which subspecies I represent. I'm a hothead, not a grump. Michael Hardy 20:39, 21 February 2007 (UTC)

Probability notations

Hi all! It would be a nice thing to try to set some rules concerning notation for the probabilty and expectation symbols. In the various probability/statistics articles I've seen at least three notations: $P,E$, $\mathbb {P} ,\mathbb {E}$ and finally $\mathrm {P} ,\mathrm {E}$. Personally, I prefer the latter, as it's the accepted notation of the scientific community (sometimes the letters are bold, i.e. P and E but always straight). I have not seen nevertheless any guide that woud explain such a thing. Some article even go as far as to right $Pr$... Let's make a public discussion about this resulting in some agreement and guide for wikipedia math community. Amir Aliev 21:05, 21 February 2007 (UTC)

Consistency would be nice, but I dunno that there's a problem. I've seen almost all of those notations in print in various places ($\mathrm {E} ,\mathbb {E} ,E$ and $\mathrm {P} ,P,\mathrm {Pr} ,Pr$). I can't remember whether I've seen $\mathbb {P}$, though. Lunch 21:17, 21 February 2007 (UTC)

$\mathbb {P}$ gets used alot. The most consistant place I have seen it used is in financial mathematics to distinguish risk-neutral probability measure from the physical probability measure.Thenub314 00:43, 22 February 2007 (UTC)

Could you please some decent sources with $P,\mathrm {Pr} orPr$ ? Nevertheless, the fact is that we should pick only one notation. Amir Aliev 21:27, 21 February 2007 (UTC)

There are two extreme positions one can take with respect to notation conventions. One would be to have none. This means each article would be responsible for explaining the notation it uses (not a bad idea anyway). Another would be to standardize everything. The problem with the former is that it can confuse a reader browsing through related articles. The problem with the latter is mostly one of agreement: people use different conventions and many have strong feelings about one over another.

We should have one notation for all as wikipedia as a whole is one piece of work, not the collection of individual articles. Otherwise, it will be disastrous for the reader. Moreover the convenience of the reader certainly outweights the convenience of the writer. Amir Aliev 19:05, 22 February 2007 (UTC)

It's certainly true that five different probability theory books will use five different notations. So how do we declare one as being better than another? The few notation conventions that WikiProject mathematics has laid out in its style guide seems to be relatively uncontroversial since they agree with a majority of sources out there. (The glaring exception seems to be the use of "Dih" for dihedral groups. I don't have any idea about that one; the discussion for that decision must have taken place before I started hanging out around here.)

So this leads to a more general question. Is there some magic number that tells us what percentage of textbooks have to agree on a notation before we declare it here as a convention? Alas, for probability theory, the answer to that question may not be good news since there seems to be a lot more disagreement in that discipline, even for basic concepts like P and E. VectorPosse 22:49, 21 February 2007 (UTC)

Well, then we should organize some sort of election, for example every interested user citing some book on probability (conceivably the one they like most) and then we will count the notations in this books. It would be very interesting for me because I still don't know enough modern works from the respected authors with notation other than straight P and E. Amir Aliev 19:44, 22 February 2007 (UTC)

The universal convention I have seen for dihedral groups is D_n, and I recall no discussion ratifying the Dih notation. Sometimes things sneak in that should be removed; this is such.

Wikipedia as a whole depends more on collegiality and consensus than on conventions rigorously enforced. Sometimes we're lucky, and find almost universal agreement in current practice. For example, the ratio of circle circumference to diameter is denoted by π. Sometimes most of the English-speaking world agrees, even if others do not. For example, the unit interval including 0 but excluding 1 is denoted by [0,1). (Elsewhere, [0,1[ is used.) A great deal of mathematics notation seems to fall into these two categories. After that, things get more complicated. Sometimes an older convention has largely been displaced by a newer one, but it is important to know both to read the literature. For example, proofs once often ended with Q.E.D., but now commonly end with a block character. Sometimes different subfields or conceptual schools prefer their own convention. For example, algebraic topologists may write Z₂ where number theorists would write Z/2Z. Finally, things get simple again, with "conventions" that are used by one editor alone; these we discard.

The editor of an article may not be aware that different conventions exist. When we know, our cardinal rule is to be kind and clear and helpful for the reader. A nice example of this can be found in Fulton & Harris, Representation Theory: A First Course, ISBN 978-0-387-97495-8. On page 100 we find "Remarks on Notation", which says:

A common convention is to use a notation without subscripts or mention of ground field to denote the real groups:

O(n),   SO(n),   SO(p,q),   U(n),   SU(n),   SU(p,q),   Sp(n)

and to use subscripts for the algebraic groups GL_n, SL_n, SO_n, and Sp_n. This, of course, introduces some anomalies: for example, SO_n R is SO(n), but Sp_n R is not Sp(n); but some violation of symmetry seems inevitable in any notation. The notations GL(n,R) or GL(n,C) are often used in place of our GL_n R or GL_n C, and similarly for SL, SO, and Sp.

Also, where we have written SP_2n, some write Sp_n. In practice, it seems that those most interested in algebraic groups or Lie algebras use the former notation, and those interested in compact groups the latter. Other common notations are U^∗(2n) in place of our GL_n H, Sp(p,q) for our U_p,q H, and O^∗(2n) for our U_n^∗ H.

Very helpful; I may not know what to write, but at least I have a fighting chance of understanding what I read! My suggestion here is

1. Write what you know.
2. Help the reader.
3. In case of unfamiliarity/conflict, use the talk page.
4. For wider input, ask here.
5. For decisions vitally affecting many articles, propose a convention.

Be prepared for both surprises and cranks. As Richard Feynman said, "Keep an open mind, but not so open that your brain falls out." --KSmrq^T 00:28, 22 February 2007 (UTC)

I see that the notations listed above do not include this:

$\Pr \,$

produced in TeX by \Pr .

Fropuff made a good suggestion on the talk page for the Manual of Style during the flapdoodle with the physicists over the difference between := and ≡. Unfortunately, nobody responded to his suggestion then. Do you think this discussion should move over to Wikipedia talk:Manual of Style (mathematics)? DavidCBryant 20:18, 22 February 2007 (UTC)

Yes, I think it's reasonable to discuss style there. Amir Aliev 21:30, 22 February 2007 (UTC)

Mathematics Genealogy Project and an Afd

I come here by way of a mathematician Johann Christoph Wichmannshausen, who is up for deletion and is in the Mathematics Genealogy Project. I am unfamiliar with the importance of this genealogy tree, but I notice that a number of academics provide their "genealogy" on their personal website, so my initial assumption was that people higher up in the tree should be considered notable by default. Is that reasonable? Are there some rules of thumb that can be used to assist in determining WP:N using the "Mathematics Genealogy Project" data? John Vandenberg 00:36, 22 February 2007 (UTC)

Labyrinthine processes

While reviewing some of the "new" math articles I ran across this one. Someone hit it with a "cleanup" tag in November, 2005. The tag exhorts editors to "discuss this issue on the talk page". Interestingly, the talk page is still a red link, 15 months after the tag was placed. Apparently the person who tagged the article didn't even care enough to list any specific concerns right then and there, on that talk page. Like a graffiti artist, he tagged the article and moved on.

Last week I reviewed an article consisting of 28 words (plus 107 words of encrustations from various templates affixed by editors who apparently don't think others can judge a page unless there's a neon sign on it). I put a PROD tag on that one, but one of the author's sockpuppets deleted the tag, so I had to learn about the AfD process. Now the article itself (135 words, including the barnacles) is gone, and in its place we have a (roughly) 350-word archived discussion.

I understand why some of this happens. Maybe it's just that I haven't been here long enough to get used to it yet. But it seems that some of these processes aren't really helping to make Wikipedia any better. Can some of these labyrinthine processes be straightened out, or even eliminated, somehow? For example, could the code underlying a "cleanup" tag prevent its insertion while the associated talk page is a red link? If somebody really thinks an article needs cleanup, shouldn't that editor be encouraged to identify a specific problem before waving a big red flag at everybody else? DavidCBryant 16:25, 22 February 2007 (UTC)

Sounds like everything unfolded as it should. Your AfD was the right thing to do, and everyone who participated agreed with you. If you have a page on your watchlist, and someone adds a cleanup tag with no accompanying text, just write to them and complain. This nearly always gets a response. If there is no response, put something on the article's Talk page and then remove the tag. The topic of Wikipedia:Deletion is under constant review, and a large percent of the complaints are about inappropriate deletion. Sounds like you have the opposite complaint, 'inappropriate retention'. The other article you mentioned, Prefix codes, might be a candidate for deletion. It seems disorganized; any valid material would find a better home elsewhere. EdJohnston 16:48, 22 February 2007 (UTC)

I would vote very strongly against deleting Prefix codes. It is an important topic in coding theory. I did some work on cleaning it up this morning but it still needs more. —David Eppstein 17:52, 22 February 2007 (UTC)

I agree with D. Eppstein here. "Prefix codes", otherwise known as "prefix-free codes", are important in Kolmogorov complexity as well as in coding theory. The article in question just needs to be cleaned up.

In general, I give others about a week to comment on cleanup tags that are so vague as to be useless, and remove the tags if no comments are forthcoming. Look at the recent history of Turing degree for an example. But I think eliminating the tags from WP would be a losing battle to fight. CMummert · talk 20:19, 22 February 2007 (UTC)

I'm not sure precisely which processes you thing are troublesome, but I would like to defend the use of cleanup tags. I agree that it can be frustrating to see a cleanup tag on an article when you have no idea what was meant to be cleaned up, but I'd say that the person that added the tag probably thought it was clear. As for not 'think[ing] others can judge a page unless there's a neon sign on it,' you should realize that putting the cleanup tag on a page also puts the page in a category (Category:All pages needing cleanup) so that people who are looking for something to do can pick out an article that needs help.

As for the deletion process: it can be a little annoying to have to go through a week's debate for an article that you know needs to be deleted. But, then, "it's not what you know, or don't know, but what you know that isn't so that will hurt you." Better to go through a week's worth of tiresome debate than delete an article that should be kept, I think. --Sopoforic 20:55, 22 February 2007 (UTC)

The description of that category notes "This category exists primarily as an aid to bots and other automated processes." And it is correct - Jitse's bot will notice if a math article is added to the category and note it in the daily update. There is no legion of editors poring over the actual categories to fix all articles with maintenance tags. CMummert · talk 21:02, 22 February 2007 (UTC)

Eh, well, I mostly meant people doing that sort of thing--other wikiprojects also have listings of articles needing cleanup that fall within their scope. But, some people do, I think, look at the very old categories in Category:Cleanup by month to clean up things that have been sitting for a while. I try to, anyway. --Sopoforic 21:15, 22 February 2007 (UTC)

I meant to point out there is a list maintained by Jitse's bot that lists only math articles that have been tagged. It is much more tractable than the general categories. CMummert · talk 22:07, 22 February 2007 (UTC)

Request for Comment

Talk:Indian_mathematics#Request_for_comment:_Reliable_Sources_for_Indian_Mathematics Feedback is requested for a problem on the Indian mathematics page, where two users have a disagreement about what constitutes reliable sources for claims in the article. 05:29, 23 February 2007 (UTC)

Power sum and Power Sum

There needs to be some merging with the articles Faulhaber's formula, Power sum and Power Sum. I don't know that much about mathematics to clean those up. --Montchav 11:22, 24 February 2007 (UTC)

Thanks. I made Power Sum redirect to Power sum. No information was lost since the text at Power Sum is contained at Faulhaber's formula which is linked from Power sum. Oleg Alexandrov (talk) 16:18, 24 February 2007 (UTC)

Categories for number-theoretic properties

Many articles about special classes of natural numbers are categorized in Category:Integer sequences, apparently solely because the numbers in the class form a sequence. See for example Practical number, Vampire number, or Square-free integer. I think it would be better to have a Category:Number classes with subcategories Category:Base-dependent number classes and Category:Divisor-based number classes (and, of course, appropriate cross-references between "class" and "sequence" categories). Several articles currently in Category:Number theory would also be moved to the subcategory, leaving only very important or well-known classes such as Prime number or Perfect number as direct members of Category:Number theory.

Any reasons why this would be a bad idea? Any better suggestions for category names? Category names are cumbersome to change, so it would e best to get them right from the start. –Henning Makholm 20:39, 24 February 2007 (UTC)

As far as I can see, the articles concerned are about sequences of integers - so why not just leave them in Category:Integer sequences or the sub-category Category:Base-dependent integer sequences ? Any more complex or subjective classification scheme will be poorly understood (how do you distinguish between a "sequence" and a "class" ? how you define "important or well known" ?), and you will quickly get articles appearing in the "wrong" sub-category or being put in the top level category by default. Gandalf61 14:28, 27 February 2007 (UTC)

I don't see why the distinction should be complex subjective at all. If one can determine from the definition of the class whether a given number is a member of it without needing to know anything about what the other members are, then it is only a sequence in the trivial sense of being a subset of the natural numbers. This is true for all of the three examples I gave. Why should someone who wants to learn about square-free numbers have to look in a category about sequences to find it? Expecting users to be able to think "sequence" when what they have in mid is just a property with no inherent sequential features, now that is complex... –Henning Makholm 03:20, 28 February 2007 (UTC)

Enneper-Weierstrass parameterization formula

The article Enneper-Weierstrass parameterization needs some quick cleanup that I am unable to provide. It says:

Given complex-valued functions f(z) and g(z), parameterize minimal surfaces by taking the real part of

∫ (f(x)(1 − g(x)²), i*f(x)(1 + g(x))², 2f(x)g(x)).

The formula here needs to be re-typeset, but it also does not appear to be strictly correct: where are the differentials? What are the limits of integration?

-- Dominus 08:09, 27 February 2007 (UTC)

Here it is typeset.

$\int \left(f(x)\left(1-g^{2}(x)\right),\mathbf {i} f(x)\left(1+g(x)\right)^{2},2f(x)g(x)\right)$

The MathWorld version (here) takes f(z) and g(z), where r = re^iφ, and writes

${\begin{bmatrix}x(r,\phi )\\y(r,\phi )\\z(r,\phi )\end{bmatrix}}=\Re \int {{\begin{bmatrix}f(1-g^{2})\\\mathbf {i} f(1+g^{2})\\2fg\end{bmatrix}}\,dz}.$

It also has problems, including the use of z in different ways on the left side and the right. More reliable is

${\begin{aligned}x_{k}(\zeta )&{}=\Re \left\{\int _{0}^{\zeta }\phi _{k}(z)\,dz\right\}+c_{k},\qquad k=1,2,3\\\phi _{1}&{}=f(1-g^{2})/2\\\phi _{2}&{}=\mathbf {i} f(1+g^{2})/2\\\phi _{3}&{}=fg\end{aligned}}$

with c_k constants, g(ζ) a meromorphic function on a domain D in the complex ζ-plane, f(ζ) an analytic function on D with the property that at each point ζ where g has a pole of order m then f has a zero of order 2m, and D either the unit disk or the entire plane. (Lifted from the Encyclopedic Dictionary of Mathematics, second edition, ISBN 978-0-262-59020-4.)

I claim no expertise in minimal surfaces, so someone may want to check this and fix the article. --KSmrq^T 15:23, 27 February 2007 (UTC)

Many thanks. I should have thought to look at Mathworld myself. -- Dominus 15:53, 27 February 2007 (UTC)

I have changed the article; I would be grateful if someone would check my changes for errors. -- Dominus 16:28, 27 February 2007 (UTC)

Mar 2007

Metric spaces, et al

I'm thinking that we might want to reorganize slightly a set of articles. In particular:

• Ultrametric space
• Quasimetric space
• Pseudometric space
• Semimetric space
• Hemimetric space (though the book I'm using calls it quasipseudometric, this one does seem more common from a google search)
• Prametric space

Notice that we have Metric space and Metric (mathematics) both. I think that, if it isn't justified to have both an article for the (quasi)(pseudo)(hemi)(semi)(grape-flavoured)metric as well as the corresponding space, the main article ought to be for the (...)metric rather than the space, as the metric is the more 'basic' object.

It wouldn't really be much work to rewrite the articles to match this, but I'd like opinions on whether it's a good idea before I do such a thing. Also, it seems to me that regardless of whether these are to be moved as I suggested, we need to use consistent terminology throughout this set of articles. I can look into fixing this later today. --Sopoforic 11:51, 25 February 2007 (UTC)

Regularizing the terminology between these articles is a good idea, but I don't see the need to merge the articles on metrics and metric spaces. For important topics like this, there is so much to say that it is easier to split it into two articles, as long as the articles are not covering the same information. In this case, metric covers topics like equivalence of metrics, while metric space includes discussion of the topological properties of the spaces, so there is little redundancy. There is something to be said for articles that are narrow enough that they can be read in one sitting, and there are guidelines on article size that encourage medium-length over long articles.

There are lots of other examples of similar splits. We have Exponentiation/Exponential function, Arithmetical set/Arithmetical hierarchy, etc. CMummert · talk

You misunderstand me. There is currently only one article for each of those (i.e. we have Quasimetric space and not Quasimetric). I think that we should either have two articles (both Quasimetric space and Quasimetric) or that the article should be called by the metric, not by the space (i.e. Quasimetric instead of Quasimetric space). That is to say, I agree with you; do you think we should change the names of the articles? --Sopoforic 14:46, 25 February 2007 (UTC)

I see, I did misunderstand. I don't think the names matter too much, because redirects are cheap. But KSmrq pointed out below that many of the other topological space concepts are in articles with names like regular space, so the current titles for the various types of metric spaces seem to match some informal convention. CMummert · talk 20:52, 25 February 2007 (UTC)

I think both names should exist, one a redirect for the other, and that the primary name should be consistent across these articles (also e.g. injective metric space). But I don't care which convention you use to make them consistent. —David Eppstein 16:46, 25 February 2007 (UTC)

Many notions in topology named "foo" are under "foo space"; for example, "compact space" instead of "compact" (which redirects). Perhaps the idea is that to define compactness we need a space, so the idea does not stand alone. We can — and should — separate "metric" and "metric space". Partly this is because "metric" can stand alone, and partly because the technical definition of a metric used to define a metric space is only one usage. This argument does not apply to the examples that began this discussion, which do not really stand alone nor have significant other uses. --KSmrq^T 18:28, 25 February 2007 (UTC)

It's not clear to me how a metric can stand alone (what is the point if it isn't defined on any set? it seems meaningless), but I am far from an expert. I only came across these articles because the topics came up in a book and I thought I'd see what we had. The motivation for my asking this is this: take a look at Pseudometric space. It is mentioned in the lede that this is a set together with a pseudometric, but the rest of the article is spent talking about the pseudometric in particular, and not the space, which made me think that it might be appropriate to rename the articles. But the feeling seems to be that they are fine as they stand, so I'll leave them be. Thanks for your input. --Sopoforic 02:12, 26 February 2007 (UTC)

As content is added to articles, their focus can often change in major ways, making any given title seem odd-fitting. If you expand these articles, say, doubling their size, then a title change may be warrented -- or maybe instead an article should be split in two. For now, the titles fit, they seem consistent, and they leave room to grow. Its an organic process. linas 03:34, 2 March 2007 (UTC)

LT code

Since Oleg included Category:Coding theory in the list of math articles a few days ago, I've been trying to review all of those new articles, to be sure they make sense. LT code doesn't make much sense to me, the way it's written. I'd appreciate an independent review by somebody here who understands algebraic coding theory.

From reading a little bit about "Luby Transforms" from other sources, it seems the best way to describe them is to think of the encoding and decoding process in terms of the "Exclusive Or" operation. Since the exclusive or of any bit string with itself is identically zero, it's pretty easy to understand how this randomized encoding strategy works. But I sure can't get that out of the existing article, no matter how hard I try.

I think I understand LT codes well enough to rewrite the article. But I'd appreciate some reassurance from someone who has previous experience with them. Thanks! DavidCBryant 01:02, 26 February 2007 (UTC)

I have no experience with these beyond having seen Luby talk about this stuff once years ago. But I think the relevant source to cite for this, among Luby's many erasure code papers, may be the FOCS 2002 one entitled LT codes. —David Eppstein 01:35, 26 February 2007 (UTC)

Thank you for the citations, David. I also found a few reasonably well-written articles that are freely available on the web, and I've finished rewriting LT code. I think it makes more sense now, but would still welcome a review by anyone who likes coding theory. Interestingly, I ran across an online article from which the original Wikipedia article was probably cribbed. At least the style of description, with bins and balls and edges and graphs, is very similar. DavidCBryant 01:25, 2 March 2007 (UTC)

Category:Important publication

I nominated Category:Important publication and all its subcategories for deletion at Wikipedia:Categories for discussion/Log/2007 February 28. Comments welcome. Oleg Alexandrov (talk) 03:21, 28 February 2007 (UTC)

There is currenlty a confusing number of top level mathematical book categories with considerable overlap. We have

• Category:Mathematical literature - traditional top level cat
• Category:Mathematics books - the main sub cat
• Category:Mathematical publications - a rather under used cat which had only 4 entries which I've now emptied.
• Category:Mathematics publications a renamed version of Category:Important_publication_in_mathematics per a CfD a few week ago.

Personally I think Category:Mathematical publications is a better name for the lop level cat than Category:Mathematical literature as literature generally makes me think of fiction. --Salix alba (talk) 09:56, 1 March 2007 (UTC)

Maximal independent set

I notice that Independent set is redirected to by Maximum independent set, and has 30-40 references. Since Maximal independent set is somewhat stubby and has only one reference (excluding lists), would it make sense also to merge and redirect this one? If not, I'll add enough of a definition to Independent set to refer back to it. Hv 07:11, 28 February 2007 (UTC)

I think it would make more sense to make maximal clique (currently a redirect to clique problem) and maximal independent set point to the same place, since they are complementary. I think there's enough material in both of them to make a real article rather than having to combine with other clique and independent set topics. For instance: any graph has at most 3^n/3 of either type of set (Moon and Moser; see also [8]); algorithms for listing all of them in polynomial time per set (see references in [9]); planar graphs and chordal graphs both have O(n) maximal cliques though that may have many more maximal independent sets (and chordal graphs may have many more non-maximal cliques); the number of maximal independent sets on a path or cycle is counted by the Padovan sequence or Perrin sequence [10]. I don't have time to write all this in appropriate detail for an article tonight, but could probably get to it some time in the next few days if nobody else does. Though, the level of self-cites in what I've listed here may mean that someone with less of a conflict of interest would be more appropriate as an unbiased writer... —David Eppstein 07:56, 28 February 2007 (UTC)

Ok, I've added the definition and backref in independent set. If you are moved to write up the detail, I'd be happy to review it (leave me a message) from the POV of someone almost completely unversed in graph theory, but I guess you'd need another expert in the field to properly judge conflict of interest. Hv 08:24, 28 February 2007 (UTC)

I've now completed a major rewrite of the article, and redirected maximal clique to point to it. I'd appreciate any constructive criticism anyone might have, especially regarding the two self-citations. —David Eppstein 02:15, 2 March 2007 (UTC)

Overfitting, Data-snooping bias, Data dredging, Testing hypotheses suggested by the data

The following four articles:

• Overfitting
• Data-snooping bias
• Data dredging
• Testing hypotheses suggested by the data

overlap and should be merged. Statisticians call it data-snooping bias when it's accidental, data dredging if it's intentional (and data mining, before that term got taken over for something else). Testing hypotheses suggested by the data describes the same thing, and also doesn't seem to be a commonly used phrase. Overfitting is what it's called if an algorithm did it (through overparameterization) rather than a human (through pattern recognition), and indeed what the machine learning community calls it. The machine learning community have studied overfitting ad nauseum since it's the problem with tuning parameters to any supervised learning algorithm. In machine learning you always partition data into a training set and testing set, and even use cross-validation (the data dredging article calls using two sets of data "randomization"; "partitioning" would be a better descriptor).

I can see keeping overfitting separate since it's an extreme version of data-snooping bias, but the other three are definitely mergeable. Thoughts? —Quarl ^(talk) 2007-02-28 08:49Z

I tend to agree with mergeing, but keeping overfitting seperate as it is a well used term. Statistical bias is currently a redirect to Bias (statistics) which is a short disambig. Maybe these articles would be better treated as a longer article on Statistical bias? --Salix alba (talk) 08:21, 1 March 2007 (UTC)

I think the three articles ought to be merged, probably under the "data dredging" title, with the others as redirects. I'm not so sure about lumping them in with "statistical bias", since that term is often used to refer to systematic sources of error, or bad data collection techniques, in my experience.

I think a classic example of "overfitting" is in the field of econometrics. I remember looking at some big econometric models, with maybe 350 variables input, and 600 "predicted", and maybe 940 different linear equations tying all these things together. The "technique" was to collect all the data (including "predictions") for past periods of time, and then to run this monster regression to minimize the squared error over all the data by treating the coefficients in the linear system as variables! I'd criticize this "model" as having very little predictive power, and no grounding in laws of cause and effect, but the guys who were building it said "We don't have to convince you – we just have to convince the NSF!" Now they're probably predicting next year's GDP, or the federal budget deficit, and I'm writing articles for Wikipedia.  ;^> DavidCBryant 01:07, 2 March 2007 (UTC)

Cross-project help, Vandalism Studies

Hello everyone. I was wondering if I couldn't ask for a little assistance from you fine people over here to look over our data at Wikipedia:WikiProject_Vandalism_studies/Study1. While the math isn't hard obviously, something might catch your skilled eyes that we'd miss. Also, if you have any suggestions of other things we should do with the numbers (been a while since college adv stats) we'd love to hear it on the talk page. Thanks you guys. JoeSmack ^Talk 17:57, 28 February 2007 (UTC)

I think that most vandalism is concentrated on high profile articles, e.g. articles about people or things in the news or articles which might be referenced in home-work assignments. I notice that Jerk, Kinetic energy, Newton's laws of motion (when it is not semi-protected), Black hole (when not semi-protected), Natural number, and Job search engine are among those which are frequently vandalized. Perhaps you need a method which emphasizes such articles. But that depends on the purpose of your survey on which I am not clear. The type of statistics needed depends on what you are trying to do.

Also, I noticed that when you computed the average time to reversion at the end, you added 14 numbers together and then divided by 30 which seems odd. JRSpriggs 10:21, 1 March 2007 (UTC)

That (14:30) looked strange to me too, JR. But it's just an artifact of the way they're doing arithmetic -- the fourteen items are subtotals, and there really are 30 instances (possibly 31? one item may have been misclassified) of vandalism in their data. Details are on this talk page. DavidCBryant 12:05, 1 March 2007 (UTC)

Monkeying around at FA

The effort to remove Infinite monkey theorem from FA has resumed at Wikipedia:Featured article review/Infinite monkey theorem, despite an admission that the original nomination is not based on an FA criterion and near-cons4ensus that the citation complaints are groundless. I think we have three courses:

• To defeat this nomination,
• To rewrite WP:WIAFA, as WP:WIAGA has been rewritten, or
• To figure out what can replace FA.

This is not, of course, an exclusive or. Septentrionalis PMAnderson 04:30, 1 March 2007 (UTC)

I recommend doing some research and improving the article based on concerns from the review process. I came up with all this without setting foot in a library or even using my journal access, and this is the first time I've taken any interest in the article. Incorporating those and similar references will make the article far better and more FA-compliant at the same time. As a bonus, writing takes less energy than arguing. Melchoir 07:03, 1 March 2007 (UTC)

My personal opinion is that there is no benefit to me or WP that justifies that time it takes to nurse articles through the FA process and keep them at FA status if they are accepted. Other editors are free to do so if they find it more valuable. The FA standards are not particularly flawed, but the review process is not collegial nor enjoyable, and the standards and their interpretation are subject to change at a moment's notice.

Salix Alba commented (this page, 09:46, 5 February 2007, above) that it might be a good idea to make an A-class rating system for the math project to recognize the best articles that we have. This would fall under the third bullet above, although it would supplement rather than replace FA. I find the idea very appealing. CMummert · talk 13:13, 1 March 2007 (UTC)

Yes, I'd also like to give something like that a try. Apparently, some of the larger WikiProjects have their own procedures for assessment and peer review. See Wikipedia:WikiProject Council/Guide#Assessment and Wikipedia:WikiProject Council/Guide#Peer review (and links therein) for some ideas. I think we should just look around what others do (which I haven't done yet), find something we like, copy the procedure and try it out. One possible problem is that maths is so specialized; there are many articles for which I couldn't possibly comment on their correctness / comprehensiveness etc. -- Jitse Niesen (talk) 04:08, 2 March 2007 (UTC)

I've just stumbles across Wikipedia:WikiProject League of Copyeditors, it might be possible to enlist their help in getting keeping FA status. --Salix alba (talk) 19:43, 5 March 2007 (UTC)

I think it's unfortunate that the quality scale, for articles that will never be on the WP main page for reasons of their subject matter, stops at A. Perhaps we should lobby for an "FA-equivalent" class, meaning "just as good as an FA, but has too narrow a potential audience to put on the main page". For a great many of our articles, that would be the correct goal. While in theory the FA process is independent of subject matter, we all know that in reality they'll never put Stone–Čech compactification on the front page no matter how good it gets. (Note that I'm not saying that particular article is of that quality now, but it could be made so, if we wanted to put the effort into it.) --Trovatore 04:31, 2 March 2007 (UTC)

I don't think we have to be so pessimistic about obscure and impenetrable topics. Laplace-Runge-Lenz vector is FA, as are the articles at Category:FA-Class MCB articles. For several of those, I can't imagine that the population of Wikipedia visitors who had the ability and inclination to read the article broke 1%. And yet, at Wikipedia:Featured article candidates/Proteasome for example, no one complained that the article was too technical, and I don't see a suggestion that it shouldn't make the Main Page. Melchoir 04:56, 2 March 2007 (UTC)

Looking around Military history A class review has

Reviewers should keep the criteria for featured articles in mind when supporting or opposing a nomination. However, please note that (unlike actual featured articles) A-Class articles are not expected to fully meet all of the criteria; an objection should indicate a substantive problem with the article. In particular, objections over relatively minor issues of writing style or formatting should be avoided at this stage; a comprehensive, accurate, well-sourced, and decently-written article should qualify for A-Class status even if it could use some further copyediting.

which seems quite sensible. --Salix alba (talk) 09:17, 2 March 2007 (UTC)

Getting back to Infinite monkey theorem, I announce that my work here is done. The benefit solely from deleting the phrases "the chance is not zero, it must be one", "each individual monkey is finite", and "probably an urban myth" already justify the effort. Obviously I also expect the article to now survive FARC. Melchoir 09:01, 3 March 2007 (UTC)

How can I draw geometric diagrams?

How can I draw geometric diagrams to include in Wikipedia (with free software)? For example, I would like to be able to make diagrams like those in Penrose tiling. Thanks. JRSpriggs 09:03, 2 March 2007 (UTC)

I haven't used the program, but there's an Open Source project page for a freeware program called "Inkscape" that may do what you have in mind. They have distros for Linux, Mac, and Windows. I see that this image in the Penrose tiling article was generated with Inkscape. The image page even includes the instructions that told Inkscape how to make the drawing. DavidCBryant 12:02, 2 March 2007 (UTC)

Please visit Wikipedia talk:WikiProject Mathematics/Graphics, where you will find some suggestions and can ask for more. Geometric diagrams come in many flavors, with tilings being rather special, and aperiodic tilings still more so. In some cases, specialized programs like Tess or C.a.R will do just what you want; in other cases, programming in MetaPost or PostScript (see Casselman) is more effective; and a catch-all graphics editor like Inkscape can either add finishing touches, or perhaps be the sole tool. (Prefer SVG output, but test to be sure the half-broken librsvg renderer used by MediaWiki produces the output you expect.) The options depend on your needs, platform, taste, and budget (Mathematica is powerful but pricey). --KSmrq^T 21:40, 3 March 2007 (UTC)

B+ rating and Wikipedia 1.0

One of Oleg Alexandrov's bots automatically updates the table Wikipedia:Version 1.0 Editorial Team/Mathematics articles by quality statistics. Here is a static version from when this message was posted:

Mathematics articles		Importance
		Top	High	Mid	Low	Total
Quality
	FA	5	3	2	2	12
	A	9	6	1		16
	GA	2	7	7		16
	B	50	47	31	13	141
	Start	22	30	30	29	111
	Stub		5	16	30	51
	Unassessed
	Total	88	98	87	74	347

There is no line for B+ articles here, because WP 1.0 does not include B+ as one of their ratings - it is a project-specific rating. There are currently 38 math articles rated B+, which is about 10% of all rated articles. The math rating template already puts all B+ articles into both the B+ and B-class categories, so B+ articles are included in the B line of the table. But this duplication does not seem to be well known.

The upshot of this is that when an article is rated B+, it is not easy to find that out except by browsing categories. There are several options here:

• Get rid of the B+ rating, and just use the B and A ratings.
• Make a separate bot to generate a different table that does include B+ articles.
• Ignore the problem

I am posting this message here to gather opinions about what to do. CMummert · talk 16:22, 1 March 2007 (UTC)

If we are going to rejigger this system, we should remove FA and GA classes from it; the fewer articles approved by those people we have the better. I defer to the graders whether they make a real distinction between B and B+.Septentrionalis PMAnderson 17:24, 1 March 2007 (UTC)

The standards for FA and the stanards for GA are different and run by different groups, and an article can achieve FA status technically even if it has not gotten GA status. GA is where all the problems are, not FA. JoshuaZ 08:02, 2 March 2007 (UTC)

Here is an example of the type of thing that can be done with a project-specific table. Unlike WP 1.0 bot, this program sorts out the B+ articles and uses backlinks to sort the articles by field. Of course there is room for improvement. CMummert · talk 20:21, 1 March 2007 (UTC)

{{Wikipedia:WikiProject Mathematics/Table}}

Looks cool. But you need to put it on a page different than Wikipedia:Version 1.0 Editorial Team/Mathematics articles by quality statistics as that one will be overwritten by WP 1.0 bot. How did you generate the above table? You're very welcome of course to use my bot's code if you find it useful. Oleg Alexandrov (talk) 05:13, 2 March 2007 (UTC)

Yes, it would be inside the math wikiproject namespace. The idea is to be completely independent of WP 1.0. I'll put a comment about the script on your talk page. CMummert · talk 05:46, 2 March 2007 (UTC)

Oh, that's a very nice table. I like it much better. One question, though. Is there a list of e.g. stub-class high-importance articles, or start-class algebra articles, or such? I think there's a tool... catscan or something... that will let me do intersections, but it'd be nice if there were already a category. --Sopoforic 06:36, 2 March 2007 (UTC)

I can certainly generate such a list using the same script. There are tables right now that are maintained by hand, and I don't want to figure out how to parse those. Also, my script does not download any articles or talk pages, so I can't fill in "comments" into the tables. But I can make a simple list. I also have to diagnose some bug in my setup. CMummert · talk 14:30, 2 March 2007 (UTC)

I see that Wikipedia:Version_1.0_Editorial_Team/Mathematics_articles_by_quality is sorted by class and then importance, which takes care of the first part. Is there anything for the second part? --Sopoforic 06:38, 2 March 2007 (UTC)

V nice. Minor point in the second table you will need an unassessed field row. If you working on a bot it might be cool to automatically generate the the field specific tables such as [[11]].

If we are redoing thing, it might also be worth considering a B- rating. While assessing article I've found that there is a big gap between Start and B. Not as useful as the B+ rating but worth a look. The reason B+ articles are currently put in both the B and B+ cats was primarily so WP 1.0 bot could do it thing and also to allow some measure of consistancy with other projects and the global table of all assessed articles. --Salix alba (talk) 07:56, 2 March 2007 (UTC)

For the time being, B+ aticles are still in the B class category; my script takes account of the duplication. I agree that, for the WP 1.0 tables, we might as well lump the B+ articles in with the B articles.

The unassessed field row would be there, except that I took care of all the unassessed articles yesterday. It will appear if there are any unassessed articles. The "none" column should also be suppressed when not needed (Oleg's script does so), but that is slightly less trivial so I didn't do it for the original proof of concept. CMummert · talk 14:30, 2 March 2007 (UTC)

The real question: which ratings are useful?

The central question here is: What ratings are useful for the project? Let's assume that that ratings themselves are useful, so the question is just how many different grades we need and what they mean. Right now, there are 5 that we can assign, which I understand as follows:

• Stub: trivial coverage, half a page or less when printed
• Start: not a stub, but minimal coverage. Could be called C-class.
• B: Obvious holes in coverage, nonstandard POV, or cryptic writing. But some areas are covered well.
• B+: Roughly equivalent to GA status. Experts will recognize holes in coverage.
• A: Excellent article. Roughly equivalent to FA status.

I find it hard to distinguish between Start class and B class. What criteria could be used to distinguish between Start, B and a new B- class? Wouldn't it be easier to just add some guidance like "When in doubt between B class and Start class, go with Start class"? CMummert · talk 14:30, 2 March 2007 (UTC)

B articles are longer than start, but still missing stuff or written from a narrow/uninformed POV. linas 00:06, 3 March 2007 (UTC)

Start-class only have one decent section, or only a couple of lines on the aspects of the topic. The quality of an article is acontinuous thing, as we're assigning discrete quantities to it, so there will always be borderline cases. Tompw (talk) 22:51, 6 March 2007 (UTC)

Prime factorization of 1?

I made the following change to the Integer factorization:

By the fundamental theorem of arithmetic, every positive integer greater than one has a unique prime factorization. One does not have a prime factorization because one is not defined as a prime number and therefore can not be written as the product of any prime numbers. [12]

An IP editor reverted this leaving this comment on the edit summary: The empty product is 1 (See explaination in the article on the fundamental theorem of arithmetic)[13]

I don't understand how this makes my contribution incorrect. I understand that 1 is the product of no numbers (like how anything to the zero power is 1). But the question of prime factorization is whether a number can be written as the product of prime numbers, so how does that fact say anything about whether 1 can be represented in such a way?--Jersey Devil 17:52, 2 March 2007 (UTC)

The empty product is a prime factorisation, because all the factors in the empty product are primes (trivially). In other words, 1 can be written as the product of 0 prime numbers. Perhaps slightly confusing at first, but quite reasonable, and it makes everything neater. JPD (talk) 18:06, 2 March 2007 (UTC)

Yoink. Melchoir 18:17, 2 March 2007 (UTC)

There's no point in arguing with the empty-product crowd, Jersey Devil. You can point out to them all day long that the sentence "1 can be written as the product of 0 prime numbers" means the same thing as "1 cannot be written as the product of any prime numbers". And they won't listen, or they'll tell you you're wrong. When you ask them to write down 0 numbers and they don't do it, and then claim that they've already done it, and there's "nothing" to it, you can begin to grasp the difference between that kind of formalistic logic and the kind of thinking you and I do. DavidCBryant 19:03, 2 March 2007 (UTC)

No it doesn't. 0 is not the empty set. Septentrionalis PMAnderson 20:16, 2 March 2007 (UTC)

Does "0 can be written as the sum of 0 integers" mean the same thing as "0 cannot be written as the sum of any integers"? -- Dominus 21:01, 2 March 2007 (UTC)

No, it doesn't mean the same. The first statement is true (because the empty sum is defined as 0). The second one is false. Counter example: $3+(-3)=0$. Ocolon 21:07, 2 March 2007 (UTC)

If you think the prime factorization of 1 is confusing, just try thinking about the prime factorization of 0. It's divisible by every prime power! —David Eppstein 19:06, 2 March 2007 (UTC)

This discussion highlights a phenomenon we've seen many times before. (Until recently, I was involved in a similar discussion about 0^0 at the page Exponentiation.) The point was made there, and I'll make it here, that we here at Wikipedia need not argue about the logic of any given convention. We report what is out there in the literature. On the Exponentiation page, we have a section on 0^0 that describes two different conventions in the literature without judging either as being correct or incorrect. (We mathematicians have a hard time admitting that sometimes two different statements can both be correct, Continuum hypothesis aside, since they are matters of convention.) Why not the same thing here? If there are books that say that 1 can be written as the product of primes, fine. Just report the source of the statement. Alongside it, we absolutely have to report that most books restrict any such statement to integers n > 1, whether they "need to" or not. VectorPosse 23:51, 2 March 2007 (UTC)

Off topic here -- the matters you are discussing are matters of convention; the continuum hypothesis is not. --Trovatore 00:05, 3 March 2007 (UTC)

Fair enough.  :) VectorPosse 00:52, 3 March 2007 (UTC)

For a source, see Hardy and Wright: Number Theory. As far as I know, there is no source which denies that 1 is an empty prime product. Editors can write around this convention if they like, but other editors are likely to follow it; it is simplest. Septentrionalis PMAnderson 03:49, 3 March 2007 (UTC)

Strayer's Elementary Number Theory states the Fundamental Theorem of Arithmetic only for integers strictly greater than 1. Then there is an exercise explaining why the statement of the theorem would be (should be?) untrue for 1. So there's the opposing sources I mentioned above. By the way, I'm not sure a book has to deny explicitly that 1 is an empty prime to be a source for the convention that we should restrict attention to integers greater than 1. I think it's also a matter of debate which convention is simpler. (Simpler in terms of the necessary hypotheses, or simpler for the lay reader?) But maybe this discussion has reached the point at which it should be taken to the talk page. VectorPosse 06:10, 3 March 2007 (UTC)

I've now posted my thoughts on the matter at Talk:Fundamental theorem of arithmetic and Talk:Integer factorization. Feel free to chime in at either of those places. VectorPosse 06:37, 3 March 2007 (UTC)

Every positive integer less than 11 can be written as 2^k·3^m·5ⁿ·7^p for some non-negative integers k, m, n, and p. In particular, 1 = 2⁰·3⁰·5⁰·7⁰. Get the picture? JRSpriggs 12:42, 3 March 2007 (UTC)

Sorry, but I'm not clear who is meant to "get the picture". Are you talking to me or someone else in the thread? For the record, I agree you and with the aforementioned "empty product crowd". I'm talking about reporting multiple conventions, not arguing the logic. My entry on the talk pages listed above should clarify. (A discussion seems to be forming at Talk:Fundamental theorem of arithmetic.) VectorPosse 13:22, 3 March 2007 (UTC)

To VectorPosse: I should have made it clear that I was addressing Jersey Devil and anyone else who might agree with him.

To Jersey Devil: If instead of just thinking of a product of primes, one thinks in terms of a product of powers of all (distinct) primes, then it should be clear that 1 is in no way exceptional. JRSpriggs 11:55, 4 March 2007 (UTC)

I think I get the picture: every integer n is even, since $n=2^{0}n$ and so, 2 is a prime factor of n, ergo, n is even. So, for example, 3 is the product of zero twos, and thus, 3 is even. linas 17:03, 5 March 2007 (UTC)

There is much more of a difference between saying something is a product of primes and saying something has a particular prime factor than there is between the empty product and other prime factorisations, so this smart comment really only misses the point. I can understand people objecting to the idea of empty product conventions, but the original question accepted that, and asked how that affected prime factorisations. The fundamental theorem is more importantly about uniqueness of the factorisation achieved than anything else - it is silly to exclude the case where there is no factorisation needed. The more general "product of a unit and (powers of) primes" (for any UFD) covers this without the difficulties of empty product conventions. JPD (talk) 17:56, 5 March 2007 (UTC)

Creation of a Mathematical Formulas Page

I believe it would be a good idea to add a page with formulas used in mathematics. They could be grouped into categories of different areas of math with explanations and examples of the equation. This would be of great help for many students.--Trd89 23:16, 2 March 2007 (UTC)

Go for it. It shouldn't be hard to list all three of them, lets see, E=mc2, A=pi r2 and I keep forgetting the third one. linas 00:27, 3 March 2007 (UTC)

We do have pages (e.g. the articles at Lists of integrals) like this, which are of debatable value. However, wikipedia probably isn't the place to create a list of formulae for students. Wikibooks, however, might welcome such a page. The problem with creating them here is that such lists generally won't have much encyclopedic value; they may serve as study aids or quick-reference guides, but they probably aren't appropriate for encyclopedia articles. Also, it would be very difficult to come up with appropriate criteria for inclusion. I could probably produce on the order of a hundred very commonly used formulae without half trying, and I know of whole books consisting of nothing but identities which could conceivably be included in such a list. --Sopoforic 00:49, 3 March 2007 (UTC)

This site would be used for formulas and not identities. for example what (a+b)³ factors down to--Trd89 03:04, 3 March 2007 (UTC)

Some more focus would help. A list of formulas is too broad and the content would be overwhelming. See List of formulae involving π for an example of a more specific page of this type, which has nevertheless undergone attempted deletions because some editors feel such lists are not appropriately encyclopedic. —David Eppstein 03:09, 3 March 2007 (UTC)

Would this be better suited to wikibooks? Septentrionalis PMAnderson 03:50, 3 March 2007 (UTC)

Essentially, you are asking us to take virtually all the articles on mathematics (since they all contain formulas) and strip out the words that give context and meaning to the formulas, then combine the resulting mess into one MONSTER article which be would thousands of times longer than the limit for an article. This is the dumbest idea yet. JRSpriggs 12:34, 3 March 2007 (UTC)

Please be civil. Ocolon 18:01, 3 March 2007 (UTC)

Has Political Correctness gone so far we cannot label a dumb idea as such? We all have dumb ideas, some blatantly so, others with hidden defects; it is vital that we recognized these. Claiming an idea is dumb is not the same as calling a person dumb (or worse). Which is more polite, to be told that I have spinach in my teeth, or to walk around all day with everyone noticing and pretending to ignore it? And which is better for the common good, to let a dumb idea go forward, or to kill it quickly?

The main reason I rarely call ideas dumb is cowardice; if I should be proved wrong, if the "dumb" idea leads to worthwhile results (like Wikipedia!), then the one who looks dumb is me. Since my Wikipedia credibility depends on never being wrong and always being Politically Correct, I can't afford to risk it. ;-)

Instead of chastising the language of JRSpriggs, we should applaud the courage and clarity. We are far better off removing the stigma from making mistakes than taking politeness to the point that we won't mention them. In the words of Thomas J. Watson, “The fastest way to succeed is to double your failure rate.” It is not to pretend that failures are successes! In that spirit, I would encourage JRSpriggs to verbally support Trd89's desire to improve Wikipedia while lambasting the present proposal as hopelessly naive and unworkable. Because maybe there's a germ of a good idea there, one never knows; or maybe the next, unrelated, idea will be terrific. And even if Trd89 churns out nothing but bad ideas, we would like to encourage those who might have good ones. --KSmrq^T 23:04, 3 March 2007 (UTC)

Okay. Ocolon 09:26, 4 March 2007 (UTC)

I think the idea to add formula only-pages would cause unnecessary redundancy. The formulae are already where they belong to in an encyclopedia — in those articles that handle their topic. Ocolon 18:01, 3 March 2007 (UTC)

Thinking in terms of our users, mathematical formula is probably a common search term, as a jumping off point to Lists of integrals, List of formulae involving π, List of trigonometric identities, would probably help what they are looking for quickly. --Salix alba (talk) 00:00, 4 March 2007 (UTC)

We might have a jumping-off page that links to those existing lists. However, I foresee endless trouble with such a page if some well-meaning user starts adding formulas to the page itself, and others find themselves inspired to attempt to make an exhaustive list of it (there ought to be, somewhere in project space, an essay about the danger of starting lists with unclear inclusion criteria, because someone will always attempt to make them exhaustive). I don't think it would work without a big bold self-reference saying that most formulas in Wikipedia are found only in articles about their subject and not in any list, and that this is intentional and desired. –Henning Makholm 00:08, 4 March 2007 (UTC)

See also Wikipedia:Articles for deletion/List of well known mathematical formulas. —Quarl ^(talk) 2007-03-04 09:57Z

Formulae articles suggestion

I have made the request elsewhere, but am copying a version here:

When a formula is described on Wikipedia, a one or two sentence non-mathematical introduction is included - aimed at persons who are outside their field with the given topic.

"It was developed by [abc] in [date]. This formula is used in the area of [xyz] and its purpose is to do [def]."

(Can someone archive part of this talkpage - getting slightly long).

Jackiespeel 18:54, 5 March 2007 (UTC)

Good writing, which we aspire to, does include giving English descriptions of formulas. There are a lot of articles that need to be improved, so this goal is not yet met in practice. If you find one that is particularly confusing, you may add the {{confusing}} template, but doing so does not guarantee that anyone will quickly appear to edit the article. This talk page is archived automatically, as explained at the top of the page. CMummert · talk 00:11, 6 March 2007 (UTC)

Graphs of theorem dependencies, and tables of examples

How feasible would it be to create either a graph of theorems and axioms or a crossindexed table of examples, like the one at the back of "Counterexamples in Topology"? I know it would be quite an undertaking, but either would be pretty great. Prc314 23:40, 6 March 2007 (UTC)

To do page

I wanted to help, and looked at the Wikipedia:Pages_needing_attention/Mathematics page. Is it possible to sort these items according to topic, i.e. algebra analysis etc. This would help to guide people (like me) with only special knowledge to the articles needing help much quicker. Thanks. Jakob.scholbach 02:06, 7 March 2007 (UTC)

It's not so easy. We need to devise a scheme to decide whether an article is algebra, analysis, topology, etc., and then program it. It's probably possible, but I'm not convinced it's worth the effort. After all, you can just scan the list and pick out the articles in your specialization. Granted, it takes more time and you'll probably miss some, but after you have poked around for a couple of weeks, you'll soon have a list of things that need to be done and (at least in my experience) the list always grows faster than that you can resolve the issues. -- Jitse Niesen (talk) 23:30, 8 March 2007 (UTC)

There is some progress on this front with the {{maths rating}} template. On that there is a field parameter which can be used to indicate the broad field of an article. Quite a rough tool and its not always clear which field to pick, and theres only 350 or so articles which have been graded to date. Anyway you may find Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Analysis and other pages of some help. BTW its probably time we actually did something with the field parameter, say putting those articles in a category or something cleaver with a bot. --Salix alba (talk) 00:11, 9 March 2007 (UTC)

I can say from experience that having a category would be very convenient for automatically determining which articles are assigned to each field. The current method I use to create this table is not theoretically perfect. CMummert · talk 00:55, 9 March 2007 (UTC)

Structure theorem for finitely generated modules over a principal ideal domain

Could someone review Structure theorem for finitely generated modules over a principal ideal domain? It has been recently created and caught by our bot as copyvio, but apparently it is a false positive (and would like a member of this project to review it and decide if it is notable enough for Wikipedia (as the only reference is a PDF). If it is suitable, please tag the article appropriately. If it is not, please prod, afd or inform me so that I can proceed. Thanks in advance! -- ReyBrujo 03:08, 7 March 2007 (UTC)

Took a quick look, so i can't vouch 100% for its contents. But this looks like the classic decomposition theorem for modules. I would guess it's already in some other article though. --C S (Talk) 03:19, 7 March 2007 (UTC)

I think in that case it would indeed at least deserve a renaming (or if it is somewhere else being either deleted or transformed into a redirection). I leave it to you since I suck at maths ;) -- lucasbfr ^talk 17:52, 7 March 2007 (UTC)

I'm not sure why it would be renamed. Despite the long name, that is what it's called. And while the article could use a little work, it's certainly notable and important, and therefore deserves an article. VectorPosse 19:03, 7 March 2007 (UTC)

Ok, I will remove it from the copyvio watchlist. Thanks for the help! -- ReyBrujo 20:56, 7 March 2007 (UTC)

Jimbo Wales' proposal for credential verification

Recently there has been a small media storm (e.g. [14]) over the revelation that Essjay, a bureaucrat and Wikia community manager, has misrepresented himself, in particular his credentials as a professor of theology at a university. Jimbo Wales initially stated that he regarded this as only utilizing a pseudonym; after learning more details, Jimbo came to the conclusion that Essjay had used his false credentials to bolster his arguments in editorial discussions and so asked him to resign his positions of trust (which he did). Essjay has subsequently left Wikipedia[15].

Jimbo has on his talk page proposed an optional procedure similar to Amazon's "real name" mechanism. Editors wishing to verify their credentials may do so. Jimbo envisions a related policy whereby someone stating unverified credentials would somehow be discouraged for doing so.

Now what does have to do with us? And why am I posting these comments? Well, I've been reading the comments on Jimbo's talk page with regards to this proposal. It struck me that there are several issues that our community is quite unique and perhaps suggestive of a model of how the ideal verification system should work.

Let me basically break up these issues into two groups: 1) trust-based editing, 2) dealing with cranks.

1) There have been arguments against Jimbo's proposal because people understand this (perhaps wrongly) to be about using credentials to bolster one's editing, e.g. "Your edit should be reverted because you don't have a Ph.D. and I do!" I'll try and abstain as much as possible from getting into the issues of whether this is a correct understanding or not of the ramifications of the proposal; my desire is only to explain why our WikiProject experience is relevant to the proposal. In our WikiProject we have a number of credentialed (or near-credentialed :-) ) experts. Somehow we manage to give these people the necessary respect without kow-towing to their authority, and conversely these expert editors manage to not act like such, but utilize policy to justify their edits and decisions.

One explanation for this is that such experts manage to show their expertise in their edits and are generally good at learning the relevant policies in a timely fashion. The expertise is viewed favorably by other editors, who often make the transition to Wikipedia easier for these editors. Speaking for myself, I judge an editor based on his/her edits, but find that credentials often help in understanding someone's background and expertise.

Another explanation is that we are sufficiently insulated from the rest of the community (including a number of trolls and vandals) that we don't have the same issues. This explanation is partly bolstered by the increasingly frequent disconnect between mathematics editors and long-standing non-mathematical editors in discussions on citations, articles reviews, etc. On the other hand, my experience with the second set of issues suggests that the occasional problematic editors we do deal with often require as much effort or even more effort than non-math editors deal with.

2) A number of project members have experience (either directly or indirectly) of cranks, particularly on Wikipedia. A common argument going on right now on Jimbo's talk page is whether policy by itself can handle cranks adequately. Some suggest that the use of credentials can be useful for say, mediators, in determining crankiness. It seems to me that some project members have dealt with such cranks for often very extended amounts of times (with some ongoing). This suggests that it is not as easy for experts to deal with cranks as some have asserted in response to Jimbo's proposal. In my experience, the hardest cranks to handle are the ones that offer myriad citations, sometimes to hard to obtain documents, that can take days or weeks to investigate (by going to the university library, waiting for interlibrary loan, or whatever) and refute.

I think it would be helpful for people to go to Jimbo's talk page and explain their experience, particularly with respect to these two kinds of issues. Somehow we've struck a right balance between relying on credentials but also on a person's body of editing. I think this is something the rest of Wikipedia can learn from, or at least to consider why it may not be viable for all of Wikipedia. --C S (Talk) 21:04, 6 March 2007 (UTC)

Yeah; one of the more troublsome cranks was highly credentialled - the problem was that he (Carl Hewitt) was an overly agressive self-promoter with no self-control. linas 01:11, 8 March 2007 (UTC)

The Carl Hewitt problem was deeper still. Earlier in his career he made substantial, valuable contributions to computer science at MIT. The MIT AI Lab, and MIT generally, can nurture individuals who are bright and unusual. One well-known example is Richard Stallman, who founded the Free Software Foundation, and who arguably marches to a different drummer than most. For MIT at large, a famous example is Noam Chomsky, whose major contributions to linguistics are accompanied by controversial and outspoken political views. But Carl drifted so far out of the mainstream that his own field was unwilling to follow him. He is convinced he is correct, and often asserts priority, both vigorously. Perhaps history will prove him right and everyone else wrong, but at the moment that seems unlikely. Carl is not a common crank, despite a similar disruptive pattern of behavior.

Research is often portrayed idealistically as a pure search for knowledge, innovation, and improvement. With experience, one sees that the search is not completely pure. Human beings have egos and ambitions and insecurities and complex social dynamics, as well as a broad spectrum of intellectual strengths and weaknesses. Whenever we talk, write, or listen, we are dealing with a person, not an abstract machine, and it is helpful to keep that in mind as we evolve our systems and procedures. The (impossible) goal is to support the remarkable good each person may be able to contribute, while protecting ourselves from the not-so-good.

One theory of sociology says that every group draws a boundary around itself, separating acceptable from unacceptable, with ways to (attempt to) enforce the distinction. Similar ideas appear in cultural anthropology. No doubt Wikipedia's ways will provide fertile raw material for a number of doctoral dissertations in these fields. Meanwhile, we must muddle on.

My only suggestion is vague: to combine common sense with compassion, to regard the facts dispassionately while never forgetting the humanity behind them.

We may eventually find that the mathematics community here appears to work well only because it has not been challenged to the same extent as other parts of Wikipedia. Some folks also make that claim about the remarkable scarcity of worms and viruses for the Mac OS compared to MS Windows — and have been making the same claim for decades. My suspicion in both cases is that the communities are at least as important as the systems. --KSmrq^T 06:10, 8 March 2007 (UTC)

I don't know if this adds anything, but when a new user, User:LBehounek, arrived and started editing stuff on T-norms, a quick google told me that he was a graduate student or something in the Czech Republic. After noticing a couple more edits were good, I found I didn't have to watch too closely, as he liked to make many small edits at once. Its a sort of "trust, but verify" thing. What made it much easier, though, was that the user used part of his name in the username. I think that this is more common in some communities (math, science?) than in the general population. This openness makes a big difference. Smmurphy^(Talk) 06:41, 8 March 2007 (UTC)

The 2 problems with EssJay were (1) that the credentials he claimed to have on Wikipedia got taken as fact and falsely-asserted off Wikipedia and (2) that he asserted credentials to try to gain the upper hand in a content dispute. I don't care how many Ph.D.s someone has; "trust me" is not acceptable verification for Wikipedia articles. Everyone has to cite a reliable source for content asserted in an edit. And let's say that a non-expert makes an edit that they, in good faith, think makes the article better, but unfortunately introduces a subtle error. Then the response is that the person who catches the error fixes it (hopefully in a way that still addresses the first editor's concern) and maybe leaves a polite note on the editor's talk page encouraging them to keep editing but to discuss potential changes on the article talk page first. That's the system now, and I think that it works fine. If the credential verification procedure happens, people are going to be afraid to edit sections created by someone with a higher credential, and I don't want that to happen. Do we have to create a rule or procedure every time some (insert not-nice word of choice here) finds a way to abuse the Wikipedia system?

Anyway, the problem has now been resolved, and now we're all aware to not take someone's asserted credentials at face value. That whole "fool me once..." etc. thing. I'm going to go post this at Jimbo's talk page now. Thanks for bringing it to our attention. --JaimeLesMaths ^(talk!edits) 07:11, 8 March 2007 (UTC)

Trust. When wikipedia works is it is when there is trust among the editors, trust that editors put NPOV above personal objectives, trust that people do not make false claims about their credentials. When wikipedia breaks is when the trust fails. Either when the user breaks the trust or when the administration fails to trust the users. It would be a sad day when the trust is replaced legislation. --Salix alba (talk) 09:13, 8 March 2007 (UTC)

cleanup of "independent variable" and "dependent variable"

• independent variable
• dependent variable

Both of these pages begin by suggesting that the design-of-experiments usage is the principal topic of the article. That is ridiculous. Then they treat the usage that everyone learns in high school, and independent variable gives a stupid definition by non-essentials: the variable plotted on the x-axis.

Also, there should be a conspicuous link to statistical independence, since that is where the topic of independent random variables is treated.

I'm leaning toward (1) redirecting "dependent variable" to "independent variable" and making the latter to into a disambiguation page.

• An independent variable is

• • in mathematics, an argument (input) to a function, the dependent variable being the value (output);
  • in design of experiments and various other areas of statistics, a variable controlled by the experimenter or at least one whose causal consequences one wants to consider;

• Independent random variables are treated at statistical independence.

• possibly some computer-science meanings too?

Another problem is how to direct the many links to these pages. I suspect some of them are already pointing to an inappropriate place.

Michael Hardy 22:54, 9 March 2007 (UTC)

I think the notion "dependent" in dependent versus independent variable in the design of experiments and statistical hypothesis testing is not related to the notion of statistical independence of random variables. It is an unfortunate coincidence that the same word is used with unrelated meanings in somewhat related contexts.  --Lambiam^Talk 17:25, 10 March 2007 (UTC)

It's not compmletely unrelated, but it's certainly quite a different thing. Hence the need for a disambiguation page. Michael Hardy 02:54, 11 March 2007 (UTC)

Isn't it sufficient to put dablinks at the top of the relevant articles? By the way, I followed a few what-links-here links backwards, and about half of those were completely misdirected, involving a meaning of "(in)dependent" independent of that of any the articles under discussion here.  --Lambiam^Talk 05:34, 11 March 2007 (UTC)

OK, I've reorganized it, and NOT as a disambiguation page. I moved "independent variable" to dependent and independent variables and redirected "dependent variable" to the latter, after pasting some material from "dependent variable" into "dependent and independent variables". I put in a dablink to statistical independence, where the concept of independent random variables is treated. Michael Hardy 23:49, 11 March 2007 (UTC)

References

In lots of math articles in the Wikipedia, theorems etc. are stated without proper reference. (E.g. the properties of Étale cohomology). In research articles, ideally all statements (except those the author believes to be known by everybody) are cited very concretely, i.e. [..., Theorem ...] etc. I would propose this for Wikipedia articles, too. What do you think? Jakob.scholbach 05:32, 8 March 2007 (UTC)

I guess it couldn't hurt to include theorem numbers in footnotes if the latter are already present. Melchoir 05:56, 8 March 2007 (UTC)

Étale cohomology, like all articles, should at least list some good references at the end so that readers know where to go to find an authoratative treatment. Please feel free to add some if you are familiar with the area. As with many topics, an untrained reader is likely to be unable to easily comprehend these references, even though the article itself may be understandable.

A lot of discussion has gone into the purpose and utility of inline citation in math articles. There are guidelines that document the project consensus on the issue. In practice, the consensus in the math project favors correct and useful articles with few citations over short, less useful articles that give a citation for every sentence. In practice, if you ask politely for a citation of a particular result on the talk page, somebody will usually be able to give you one (or, better, explain why the theorem is true). CMummert · talk 12:36, 8 March 2007 (UTC)

The following is a vigorous endorsement of what CMummert just said. (It is also long-winded; mea culpa.)

Something I have not seen discussed is effort. When I write on a topic I know, my first focus is on the writing. Who is my audience, what must be said, how best to say it, and would a figure help? Often I do a little research for inspiration, completeness, and fact checks. (That includes jogging my memory with things I wrote in the past!) I also like to include at least a few good references, for various reasons; WP:V, Wikipedia's peculiar approach to reliability, is not one of them. Finding and documenting those references can be a great deal of additional work beyond writing the article.

Editors who do not know a topic, who write by copying out of a text with little understanding and no knowledge of context in the field, presumably start with a reference and work forward. For some topics, this describes me, too, though perhaps having more "mathematical maturity" helps always.

Wikipedia grows in both ways. I worry that those who can only copy will force their limitations on the experts. I far prefer a solid well-written article with no references to a citation-studded article that is poorly done.

∗ Some will be shocked that I claim an article can be valuable even with a theorem that is not meticulously correct. Welcome to reality. The peer-reviewed literature contains mistakes. We don't like it, we try to avoid it, but it happens and we can usually recognize the errors and find a correction. (Though I would not like to have been in Andrew Wiles shoes before he found the fix to his famous mistake!) A well-written article serves as a kind of error-correcting redundancy; for, the better we understand what was meant, the easier it is to spot and fix slip-ups. Moreover, an appealing article will attract more readers, and more eyes will spot more problems.

References do not make a good article, they are simply one more positive factor, like figures or examples or meticulously correct theorems.^∗ In fact, my approach to references is very much like that of creating a good figure or finding a good example; what will best benefit the reader?

As to the proposal of the poster, consider two scenarios. In one, a copier found a definition or theorem somewhere, transcribed it (correctly, we hope), and included a reference. In the other, an expert patiently explained as one might teach a class, in a manner unlikely to find its way into a formal publication. Do not imagine that upon consulting the references that the clouds will part and illumination will shine through. Do not underestimate the value of an expert explanation.

Mathematics has a considerable reservoir of underground literature, such as lecture notes and unpublished manuscripts, as well as many face-to-face conversations recorded nowhere. After all, when only a handful of people in the world are investigating a specialty, these informal methods of communication are more cost-effective. Even when formal publications do exist, finding a copy can be next to impossible.

Fortunately, mathematics has one significant advantage over, say, paleontology or comparative literature. We don't necessarily need a reference to verify or refute a claim.

What we do need is clear, compelling writing, so we can understand the topic and take an interest. If sometimes that means the references are not all we might hope for, so be it; they may never be, despite our best efforts. --KSmrq^T 22:58, 8 March 2007 (UTC)

CMummert, KSmrq, the choice between attributed, inadequate explanations and thorough explanations off the top of the editor's head is a false dilemma and, I think, dangerously misleading. One can build prose that is both thoroughly explained and thoroughly sourced; the catch is that it requires more thinking and more research than one will ultimately communicate or cite. We are beginning to build examples that show that the extra effort is worth it.

On the other hand, if you think you can most efficiently contribute to Wikipedia by personally adopting a different methodology, that's fine; someone else will build upon your work. But please don't discourage other editors from being the best they can be. Melchoir 23:25, 8 March 2007 (UTC)

Sigh. Lest silence be taken to connote assent: your representation, Melchoir, of what I wrote above is a gross distortion. (I do not presume to speak for CMummert.) And I might sadly note: yet again. CMummert and I support the guidelines for appropriate references; you do not. Let's leave it at that. --KSmrq^T 07:30, 9 March 2007 (UTC)

You ask us to "consider two scenarios"; surely you will admit that is an incomplete treatment of the issue?

No, let's not leave it at that. I support the application of those guidelines of which I am aware, including WP:SCG. You, on the other hand, supported[16] just last week maintaining the Featured status of an article with zero secondary citations[17] that made concrete mathematical claims in direct contradiction to the published literature. So much for not necessarily needing references. Melchoir 07:48, 9 March 2007 (UTC)

Two more paragraphs, three more distortions; yet another waste of our time. --KSmrq^T 09:25, 9 March 2007 (UTC)

Let me guess; in your defense, you didn't actually read through Infinite monkey theorem before casting your drive-by vote-on-principle. Therefore you can't be held responsible for the details of that situation? Melchoir 09:50, 9 March 2007 (UTC)

Woah guys, can we be WP:COOL, this discussion is fast aproaching that of two pissed off monkeys. --Salix alba (talk) 11:44, 9 March 2007 (UTC)

I was perfectly happy to let it go when KSmrq called the FAR "madness"; it was just one edit to a fairly obscure page. But I was definitely pissed off by what I saw in that article. There was pettiness, speculation, and plain old inaccuracy. This from a Featured Article that had been written and maintained by some of our best editors. The bit about the zero-one law, for example, is inspired by Michael Hardy's original version of the article, which made a rather conservative statement about historical usage. Eventually, in late 2004 — I don't have the diff handy — it was explained in a badly inaccurate way by an editor whose contributions include almost no other mathematics articles, and who apparently lacked the habit of precision. The new explanation survived for more than two years, during which the article was Featured and widely read. It wasn't attributed to a reliable source, but then again, neither was anything else, so it didn't stand out. Even when its veracity was challenged on the talk page, there was no source to consult, and the error was not caught or corrected. It took someone (me) to systematically go through the article, cite what's possible, and throw out the rest in order to get rid of the problem. Every other editorial mechanism failed at this most basic of purposes: not being wrong.

I'll cool down if KSmrq acknowledges that in practice, sometimes you really do have to demand a source for something, and you can't be satisfied just because an expert thinks it's self-evident. We can go from there. Melchoir 12:29, 9 March 2007 (UTC)

Actually, I had no plans to respond further. I felt obliged to note that Melchoir had distorted my statements, but one might as well get upset with the sun rising. If he feels the voices trouble him less when he wears the foil hat, there is not much hope of convincing him to remove it. (Here's a classic example.) Having wasted far too much time in the past trying to reason with him, I do not wish to travel that road again, nor to drag others through such an ordeal. --KSmrq^T 00:05, 10 March 2007 (UTC)

I admit that I handled that situation badly, and I would do things in a very different order if a similar situation arose today. Regardless of my social missteps, I did manage to improve 0.999... in several dimensions, and I'm not talking about citation count. In the end, everybody congratulated me on a job well done. If you care about results, you can't be sore over that article. Melchoir 00:53, 10 March 2007 (UTC)

Behold a stark demonstration of the folly of arguing with foil-wearers; their inner voices overwhelm the sounds from outside. In his mind, the problem is not his bizarre idea of what falls under WP:OR, but merely his social skills in failing to convince all those who disagree. And he goes on to insist (to me, no less) that he "improved" the article and that everybody offered congratulations! It may seem harsh to refuse to debate such a person, but in fact it is hopeless to try. --KSmrq^T 12:02, 10 March 2007 (UTC)

My idea of what falls under WP:OR was stated and applied to 0.999... in an unpopular fashion. I am sorry for that, although I can't apologize for the outcome.

I have no idea what it will take to placate you on this matter. I, and at least one other editor here, have attempted to discover what elements of the old version you would like to restore, and why. To no avail. I've tried to explain that I learned from the experience; you choose not to care. Apparently even the passage of time has done nothing, and you have expressed no wishes for the future. Is there anything that might convince you to stop cherishing an old wound?

And in the event that you refuse to acknowledge that question, what do other people think I should do? Melchoir 20:57, 10 March 2007 (UTC)

Whatever the case, we can hopefully agree that Étale cohomology needs some references, if only for further reading. Also, some form of acknowledgement of the intellectual achievements of the founder(s) of the theory (Deligne? Grothendieck? Serre? Verdier?) would seem in order.  --Lambiam^Talk 13:42, 9 March 2007 (UTC)

Charles Matthews wisely stayed out of the fray and added two. (Actually, the article already referred to SGA 4¹⁄₂, with a link to our article which has extensive bibliographic information.) I have fleshed out the first two references, added more, cleaned up the equation formatting somewhat, and inserted a passing mention (per Springer) of the Künneth formula. I have not made any attempt to review the content of the article, for which not even 200 references can substitute. I would far prefer to see those who know the topic well devote their time to that than to peppering the article with citations. In that spirit, I thank Charles Matthews and R.e.b. for creating the content in the first place, with or without references. --KSmrq^T 00:05, 10 March 2007 (UTC)

KSmrq, please note that your motivations may differ from others. Whenever I write about topics that I know very well, I rarely add references, because I simply don't have them any more; I'm working from memory. I think this describes others who write on topics they know well (e.g. Charles Matthews). However, I don't much like writing about things I know very well (they bore me; I do so only out of pity for some sad article); I prefer writing about things I am learning/re-learning/reviewing. These are easy to cross-reference, because I have three texts in my lap all at once. The result is a referenced if perhaps inelegant/stilted article. So it goes. linas 00:55, 10 March 2007 (UTC)

Good point. Here's another. Some topics that I know too well I avoid touching here as much as possible, because I know what can happen to them. The little warning at the bottom of the page says "If you don't want your writing to be edited mercilessly …, do not submit it." Too true. But, motivations aside, you have repeated the two modes of creation I described early. And, as I said, I am in favor of both. --KSmrq^T 12:02, 10 March 2007 (UTC)

Gee, Linas. You must have a big lap. Or some skinny textbooks. Maybe both? ;^>

I think I can see both sides of this issue. On the one hand, if a relatively simple mathematical idea is explained well, there's hardly any reason to give a reference; either the reader is going to understand say Euclid's proof that there is no largest prime number, or else he hasn't got a future in mathematics. On the other hand, well-written articles about less familiar topics begin to look too much like OR if they don't contain at least a couple of references.

Today I spent some time researching the Hartman-Grobman theorem. I had never heard of it before, but it seemed intuitively appealing, once I understood it. I figured that the best references would not only explain the theorem – they would also indicate how the theorem got its name. Eventually I found what I was looking for. I found an open on-line copy of a contemporary peper that builds on the result of P. Hartman and D.M. Grobman, and also cites the original papers (from 1959, and 1960). I also added the references to the older papers, only one of which is available on-line (via JSTOR, and therefore not freely available to most readers).

There, I think, is the rub. An awful lot of good math papers are available on-line, for $24 a pop (unless you're a subscriber to JSTOR, or IEEE, or ACM, or Springerlink, … or you have free access somehow). Most of our readers aren't in that boat. So finding good references for a free on-line encyclopedia is a challenge. Maybe we ought to focus more on helping each other solve that problem and worry a bit less about the exact number of references a given article theoretically ought to have. DavidCBryant 02:59, 10 March 2007 (UTC)

The irony of the distortion of my remarks is that I explicitly said I like references, properly used. And as the Hartman-Grobman research story reinforces, it often takes considerable time and effort to track down the ones we want.

I may be deluding myself, but I have the impression that I am often more successful at locating information on the Internet than are many around me. Search strategies can make a big difference.

• For example, if I search for 'Hartman-Grobman theorem' I miss the sources that reverse the names. If I omit the hyphen, as in 'Hartman Grobman theorem', I get both orders. In either case the information I want may be drowned in a sea of irrelevant hits; an effective response is to insist on the phrase, '"Hartman-Grobman theorem"', not just the individual words.
• Soon I find that Hartman (1982) published Ordinary Differential Equations, 2/e, Birkhäuser, alleged to contain the theorem. If I have a good library or bookstore nearby, perhaps I can have a look, as it seems likely to be a good reference. Otherwise, it's back to the Web. But wait, perhaps it's on Amazon.com, and anyway I'd also like the ISBN.
• So I search for 'Hartman 1982 "Ordinary Differential Equations" ISBN'. Notice that the title is quoted and the ISBN is explicitly requested; in my experience both of these small details are remarkably helpful in quickly locating exactly what I want. Also, here the date helps me restrict to the second edition (and is more effective than trying to say "2nd edition"). I discover that SIAM reissued the book in paperback in 2002, March 4, with ISBN 0898715105, and that the author's first name is "Philip".
• Using this handy online tool, I quickly obtain a correctly hyphenated ISBN-13, namely ISBN 978-0-89871-510-1. Sometimes we get lucky, and Amazon lets us browse inside a book; not so here, but it's a tip worth remembering, especially when all we need is a page or two. (Another tip is to look for author preprints of journal papers.)
• Nothing I have described so far requires any subject knowledge. Sometimes that can make a dramatic difference as well. For example, this seems to be a not-too-exotic topic in ODEs, and I can locate this online book by Gerald Teschl, which discusses the theorem in §7.3. Incidentally, I deliberately did all this without looking at what DavidCBryant chose for the article.

This by no means exhausts strategies, but perhaps it gives a feel for the hunt. It is time-consuming, even online, and sometimes frustrating. There is no guarantee that any good reference is available, no matter how hard we look, for a variety of reasons. In fact, we have not discussed how we judge "good", except implicitly to prefer material that is freely available on the Web.

Both linas and DavidCBryant have told us that successfully researching, learning, and explaining a topic can be gratifying; I concur. I would add that even researching a familiar topic can bring pleasant surprises, as every day more material — both old and new — shows up on the Web. Sometimes one also has the guilty pleasure of discovering that one's own work has been put to new uses.

Let me conclude with a brief mention of how I have been writing up references. My primary guide has been WP:CITET. Although these templates are more verbose than just typing in the data, they spare me the trouble of consistent formatting, and help other editors do the same. I am currently trying the {{citation}} template, which covers books and journals and so on all together. It also supports automatic links from {{Harv}} (and {{Harvtxt}}) citations, the style I prefer. (Am I the only one who hates microscopic lists?!) It's too bad we don't yet have a Wikipedia-wide BibTeX system, but apparently the rest of the world still struggles to catch up with standard practice in the mathematics community. ;-)

One last tip: AMS may be able to help decipher those mysteriously abbreviated journal names, with this online guide.

Example: In the theory of ordinary differential equations, the Hartman–Grobman theorem, as described by Hartman (2002), characterizes solutions in the vicinity of a hyperbolic fixed point (Grobman 1959).

• Grobman, D. M. (1959), "Homeomorphism of systems of differential equations", Doklady Akademii Nauk SSSR (in Russian), 128: 880–881, ISSN 0002-3264
• Hartman, Philip (2002), Ordinary Differential Equations (2nd ed.), SIAM, ISBN 978-0-89871-510-1

(Incidentally, I have used an en dash, not a hyphen, in the theorem name — a stylistic nicety.) Enjoy. --KSmrq^T 12:02, 10 March 2007 (UTC)

(KSmrq's comment and mine are both pretty long and have the same indentation level, so I'm putting this line here to separate them. The following comment is mine, Sopoforic's)

DavidCBryant notes that many of our references are not available (to most people) for free, online, and suggests that we work to overcome this. I think that a part of this would involve collecting a list of useful online sources, of which I know there are a few (Diestel's book Graph Theory comes to mind, for that subject). A second part, though, would be providing access to those sources which are legally available, but not practically available. I have occasionally cited works that are in the public domain due to their age, but which were rather hard for me to acquire, due to being in storage, or only available through ILL, or on microfilm, or whatever other difficulties may arise. We could conceivably provide access to these sources by scanning them and linking, but I personally am not sure how I would go about it--supposedly commons is the place to go for things like that, but they don't support PDFs, and JPGs of individual pages aren't as helpful as I'd like.

I don't know whether others would be willing to put in the extra time to scan out-of-copyright sources, but I wouldn't mind doing it, if only I knew what I ought to do; it's a crime that so many public domain works are locked up in subscription services, but without some guidance, I can't help solve that. So, does anyone have any recommendations? I've access to a scanner and a university library, and I've got enough free time to scan things in. If someone will help me to learn what I ought to do, I'd happily scan in relevant sections of books and things.

But that is only one idea. I'd love to hear any suggestions others may have. --Sopoforic 21:37, 10 March 2007 (UTC)

Thank you for the generous offer. There are some details we would want to discuss (proof of copyright status, where to store, format — DjVu+OCR or PDF, cataloging, overlap with existing sources), but let's begin with: can you point us at an online catalog for the library?

Meanwhile, here are three links that may be of interest: Cornell monographs, Internet archive, UPenn list. --KSmrq^T 22:31, 11 March 2007 (UTC)

I attend West Virginia University, and the catalogue is here; I believe it is accessible to the public. Of course, I'm not limited to only those books/journals owned by this library. I can also request these things via ILL, so in practical terms I can probably get access to any article or book published after about 1850 (in fact, it would probably be easier for me to get journal articles that aren't owned by the library, due to a number of factors, although that is no strict statement). Actually, I don't know what the license for JSTOR is like, but they have many articles that are out-of-copyright; if the license permits, I (and others, I'm sure) could post those articles somewhere also. I'll get in contact with whoever is in charge of the JSTOR license at my school and see what's what. --Sopoforic 03:52, 12 March 2007 (UTC)

I have the impression that JSTOR already allows public access to out-of-copyright material, and that it only restricts more recently published content. At least, I haven't always had to go through my campus's VPN to gain access to old papers on JSTOR. —David Eppstein 05:12, 12 March 2007 (UTC)

It doesn't seem that it is. I just had someone check who isn't on the campus network, and he got a copy of the first page of the article and a message telling him to subscribe for access. For reference, I gave him this url to an article in the first issue of the American Journal of Mathematics, from 1878. --Sopoforic 05:35, 13 March 2007 (UTC)

I've finally got round to creating a Wikipedia:WikiProject Mathematics/Resources page. The aim of this page is to list good sources to help in referencing of mathematics articles. --Salix alba (talk) 09:44, 12 March 2007 (UTC)

LaTeX to Wikicode translation

A raw version of a translator is available, by joint effort of User:Oleg Alexandrov and myself. Jmath666 06:57, 25 February 2007 (UTC)

"Joint work" here means that I did the original hack of several lines and then Jmath666 took the effort to make this actually output something usable. This is an interesting way to create articles, surely much faster and more efficient than using the textbox and the "Preview" button. Oleg Alexandrov (talk) 07:08, 25 February 2007 (UTC)

If you insist on getting inline TeX out of this thing, can you at least use \scriptstyle when it's inline? Michael Hardy 03:15, 28 February 2007 (UTC)

Please explain. Jmath666 22:18, 8 March 2007 (UTC)

How about the reverse - Wikicode to LaTeX? Tompw (talk) 16:25, 1 March 2007 (UTC)

The basic stuff (sections, equations, <ref></ref> to \bibitem, but no pictures or links) would not be so hard either. I wanted LaTeX to Wikicode translator for myself, because over time I wrote some introductory material in LaTeX that may be useful. And citations are so much easier if I can just pull them from existing BibTeX databases. Jmath666 22:18, 8 March 2007 (UTC)

Not even speaking of the convenience of a wysiwyg editor instead of hacking the source. Jmath666 01:20, 9 March 2007 (UTC)

By the way, is there some permanent place to make a link on Wikipedia to such tools? Jmath666 22:18, 8 March 2007 (UTC)

There is now a separate user page for the translation. Jmath666 00:09, 15 March 2007 (UTC)

WikiProject

I've started something called the Mathematics Construction WikiProject (not in development yet), which focuses on making sure that information on an article is verifiable and attributed with reliable sources. If we can do something like this on this WikiProject, it'd be great! Sr13 (T|C) 03:03, 10 March 2007 (UTC)

Um… starting a whole new WikiProject might look suspiciously like a schism. How about making it a "department" of this Project instead, something like the examples at Category:WikiProject peer reviews? Wikipedia:WikiProject Military history seems to be pretty well-organized. Melchoir 04:44, 10 March 2007 (UTC)

Sure, that would be a great idea! Sr13 (T|C) 09:34, 10 March 2007 (UTC)

Not a good idea, unless you are looking for political trouble. Instead, focus on making sure the information in each article is correct and complete, with references that follow our guideline. That is what we really want, while what you propose is a controversial Wikipedia methodology that pretends to be equivalent. Empirical studies have shown that the more inline citations an article contains, the less likely it is that anyone will actually verify everything. (OK, so I'm not aware of any actual studies; but I feel confident that's what they would find.) We must also guard against the bystander effect. I find it telling, and troubling, that you did not propose that articles actually be verified. This is cargo cult behavior. --KSmrq^T 12:39, 10 March 2007 (UTC)

Making sure that an article is correct and complete is surely the most important consideration when deciding how to reference an article, but it is not the only thing that "we" really want. Articles should also be written to be robust against the introduction of error by future editors, to simplify accuracy disputes on talk pages, and to aid our readers in their own research. These goals are the responsibility of an interactive encyclopedia, and they aren't met just by producing a version of a given article that is true.

Given that we don't have empirical studies yet, why prejudge Sr13's idea? The worst that could happen is that the department is ineffective and gets shut down. Melchoir 00:10, 11 March 2007 (UTC)

I see...so what you are saying is that verifying should not be a specific group's commitment, but rather each Wikipedian's obligation, and this is what makes an interactive encyclopedia. Sr13 (T|C) 08:45, 12 March 2007 (UTC)

I think Melchior is actually supporting your idea. KSmrq is concerned that your project will result in a lot of articles being given the appearance of having passed through a sort of verification process when in fact they may simply have had some minimal references slapped on (or, so as not to impugn your efforts, it may be that they are properly referenced, but then later dramatically expanded, and no one adds references because "they are already there" but in fact inadequate). I, however, also think it may be a good idea to do what you propose, and for a reason KSmrq already gave: the bystander effect. I for one know that I almost never go out of my way to add references to an article with none. However, I just went on an improvement binge at triangulated category because I thought the references section was poorly written, which resulted in my adding several references in addition to reformatting the existing ones. If people all look at an unsourced article they will all think that someone else should do it, but if we have even badly sourced ones, then the inevitable tendency of people to boost themselves by correcting mistakes will lead more of them to add references. Plus, we'd have at least some references, and even if they barely support any of the claims of the article, they are at least useful for people who come to a page hoping that, if it doesn't say anything useful, it will at least give them another place to look. Which most of our articles don't really do now. Ryan Reich 21:17, 12 March 2007 (UTC)

KSmrq's cargo cult idea lit up my imagination: just like a coconut radio carved by a primitive tribe might start working if only its only carved realistically enough... "if we can only add enough ref's, then surely any article can become become factually correct..." .. this thought made me smile. Not understanding that high-tech is important for creating a functional transistor radio is like not understanding that meticulous research is needed for factual accuracy in an article. Just adding references is not enough to make it true.

It took me a bit to understand the bystander effect: just as a mob of bystanders will fail to help a victim in need of help, so an article that is obviously in failing health and factually incorrect might not be helped because it already has so many references and footnotes "standing by"... . linas 00:35, 13 March 2007 (UTC)

It depends on how you interpret the crime in this case how you can apply the bystander effect. KSmrq and you both seem to agree that having so many references "standing by" will cause people to neglect their duty to do some real research on the article. It is certainly the case that in order to take a generic math article and elevate it to something that even Brittanica would be proud to publish will take a lot of work, and that adding piecemeal references will not contribute to this. Most of our articles are not near this state, however, and in fact have no referneces at all. Even adding standard citations (you know, putting Hartshorne chapter and verse in every basic algebraic geometry article) will at least improve them to the point that they are useful as references. At least they will tell you where you might go. It will also provide a basis for further improvement, which brings me to the other interpretation of the bystander effect: I claim that in this case, the crime is indifference and that we are all bystanders, no one making even a first attempt to do something useful in the way of references. Even your and KSmrq's objections to this project (something like "people should improve articles deliberately") reflect a bystander effect: you want editors to self-select to be the one to "save" the article. But it seems to me that the philosophy of Wikipedia is that multiple incremental improvements will lead to a high-quality product, not that an article is not worth being written if it is not going to be written perfectly. I think we should not stand in the way of someone hoping to industrialize the process of making initial increments in citation. Ryan Reich 03:02, 13 March 2007 (UTC)

I have pretty much every math logic article on my watchlist; many of them are in a bad state. I can say from experience that bystanders do make edits to correct errors in these articles; many errors are corrected by anonymous IP editors or by newly registered users with very few edits.

You might be interested in this list of unreferenced math articles. I think it is unreasonable to go through and add references I have never looked at to articles whose content I am not completely familiar with. But I think it would be very appropriate, for example, for someone with a background in algebraic geometry to go through those articles. I would add the crucial caveat that the topic of the article should actually be discussed in some depth by the references added. CMummert · talk 18:56, 13 March 2007 (UTC)

Even if you're not familiar enough with an article to verify it against a reference, you could always add potential sources under a "Further reading" section. Melchoir 19:51, 13 March 2007 (UTC)

Yes, I didn't think about that. The key distinction I make is whether the editor has actually seen the reference or not (at least an online version); I feel very bad adding references to books whose existence and content I am taking on faith. CMummert · talk 13:44, 14 March 2007 (UTC)

Potential sources? I can just see it: thousands of Wikipedia articles chock-full of potential facts "verified" by citing the entire contents of the Library of Congress as potential sources.

Standard rules in academia say if you haven't personally used the original source, even if it is just a reprinting (and especially if it is a translation), you should acknowledge the source you did use; otherwise we risk a game of "Rumors". This proposal goes far beyond that nuance, into total madness. "Potential sources" is a potential disaster. Kill it now. --KSmrq^T 05:14, 15 March 2007 (UTC)

Formatting of categories

Is there any consensus how to format categories? Sometime one sees $\mathbf {A}$ (mathbf) or A, sometimes ${\mathcal {A}}$ (mathcal). Jakob.scholbach 22:49, 13 March 2007 (UTC)

And worst of all, in some articles (e.g. monoidal category) one sees $\mathbb {C}$. Ryan Reich 04:48, 14 March 2007 (UTC)

To add to my comment. $\mathbb {C}$ is clearly wrong because it conflicts with well-established notation (my personal opinion is that blackboard bold should be reserved for well-established notation, which is essentially exclusive to the various number sets $\mathbb {N} ,\mathbb {R} ,\mathbb {C} ,\mathbb {A}$ (the latter is the adele ring), and so on). There is a reasonable case that A is preferable to $\mathbf {A}$ on account of typesetting aesthetics (and an equally reasonable case that the opposite is true on account of the fact that the latter reflects a semantic distinction, namely "math variables", whereas the former is merely formatting), whereas ${\mathcal {A}}$ can be said to be preferable on account of being unlikely to conflict with anything at all (calligraphic characters are, as far as I know, not standard notation for anything, whereas bold characters are not infrequently stand-ins for the equivalent blackboard-bold character). I would endorse either A or ${\mathcal {A}}$ without preference (though of course consistently in an article) given that the overlarge PNGs we get from TeX markup are actually quite distracting. Ryan Reich 05:04, 14 March 2007 (UTC)

My preference to denote categories is sans-serif boldface, Cat.

Please note that we do not have enough alphabet and style variations to give every type of entity in every specialty its own unique look. My choice, for example, conflicts with the recommended substitution of bold for blackboard bold inline, as in R instead of $\mathbb {R} \,\!$ for the real numbers. We try to write each article as clearly as possible, adapting notation where we must, and trusting our stalwart readers to compensate for our inadequacies. --KSmrq^T 05:21, 15 March 2007 (UTC)

Yes, this is my preference, too. \mathcal is problematic with categories like Ab and for things like the reals the \mathbb seems to be much more often used than \mathbf. Should a recommendation be part of the style-guideline of math-papers? Perhaps it is also possible to introduce a tag like \cat{...}, at least in the Latex code. (If I write a paper in good old-fashioned offline Latex, this would be the first I would do. If I later need to change the layout, this is done by changing one line of code). Jakob.scholbach 16:11, 15 March 2007 (UTC)

Inductive symbol

Has anyone ever heard of this? Or should we put it up for deletion as un-notable? JRSpriggs 06:18, 22 February 2007 (UTC)

I'm from Australia and I've never come across it. darkliight^[πalk] 06:35, 22 February 2007 (UTC)

We also find in the article:

• Spoke 4: The portion of the number system for which the proof holds, e.g. n=J⁺ (positive integers)

Universal notation for integers is Z, not J. The creator contributions consist solely of this article, this image, and a new section about it added to mathematical induction (since removed). The image should die as well. --KSmrq^T 09:51, 22 February 2007 (UTC)

Spacepotato (talk · contribs) un-PRODed inductive symbol without any explanation or substantive change. JRSpriggs 08:35, 27 February 2007 (UTC)

Well, you can do that -- prod is supposed to be for noncontroversial deletions, so anyone who objects can remove it. Just means you have to go the long way around, unless there's a speedy criterion that fits. At a three-second glance the article looks like a goner, but I haven't put any more effort into it than that, so who knows. --Trovatore 08:40, 27 February 2007 (UTC)

Not that it matters much, but Spacepotato is apparently part of a crew that goes around un-PRODing everything that's proposed for deletion. Why, I'm not sure. DavidCBryant 01:16, 28 February 2007 (UTC)

Oh, a propos of nothing much, I do recall the "J" notation for the integers, from high school. I think the Houghton–Mifflin series of books use it. --Trovatore 08:42, 27 February 2007 (UTC)

I tried to put it up for deletion at WP:AFD (which I have never done before), but I think that I messed the process up somehow. Can someone fix it, please? JRSpriggs 09:58, 27 February 2007 (UTC)

The AfD process seems to be in order. I would suggest an effort to clean up mathematical induction which is not much better than the this one. The intro has too many advanced topics. The informal statement should state induction for the positive integers, not infinite sequences. The worked out example unnecessarily introduces the confusing notion of an empty sum (just start with n=1), and the rest of the article is an unorganized jumble of ideas.--agr 00:12, 28 February 2007 (UTC)

As you can see at Wikipedia:Articles for deletion/Inductive symbol, it was deleted. And now, its associated image is also up for deletion as an orphan image. See Wikipedia:Images and media for deletion#Image:Inductive.gif (see old discussions for March 4). JRSpriggs 04:56, 8 March 2007 (UTC)

The image itself was deleted[18], although somehow the image page still exists.  --Lambiam^Talk 09:51, 15 March 2007 (UTC)

I have to agree with agr that the mathematical induction needs cleaning up. The current mess is a disgrace! It should focus on the simple case of induction on the natural numbers, possibly also including structural induction, but all talk of transfinite induction needs to be moved to the transfinite induction page. Which also could use some cleaning up, but that is a topic for talk:transfinite induction perhaps. I admit I am hesitant to dive in and do something here; afraid of sticking my hand in a wasps' nest. Hanche 17:54, 17 March 2007 (UTC)

Back to manual archiving

I removed the Werdnabot invocation. I have been following Werdnabot closely; and it just has too many bugs that manifest themselves in unexpected ways. Like on Tuesday, it did not put any edit summaries into its edits for no apparent reason. Thus we go back to manual archiving. JRSpriggs 08:10, 7 March 2007 (UTC)

By the way, Werdnabot (talk · contribs) has been down (blocked) and appears likely to stay that way. However, there appears to be another bot that we might use for archiving — MiszaBot II (talk · contribs). Has anyone had experience with MiszaBot? JRSpriggs 09:07, 16 March 2007 (UTC)

I looked into it a little yesterday because it looks promising. The code is still under development, and the bot was speedily approved when WerdnaBot was discontinued. The talk page User talk:Misza13 shows one or two bugs in the last two days. So maybe we should wait a couple of weeks until the kinks are worked out. CMummert · talk 11:43, 16 March 2007 (UTC)

OK. And thanks for doing the manual archiving here. JRSpriggs 07:13, 17 March 2007 (UTC)

Silly pictures

2 or 3 years ago, before Wikipedia was as popular/well known/... as now, I looked at the Mathematics and Computer Science articles and was extremely impressed. I remember noting a correction of a fault in a Taylor/MacLaurin series. It was no more than minor proof reading but within a day somebody had replied "True, why didn't you correct it yourself?"

A couple of years on it all seems to be going seriously downhill. Hard to believe but it just might be better to divide the subject into "Mathematics" and "Popular Mathematics". In the Mathematics section there are NO links to JAVA/COBOL/IGNORANT animations - that sort of nonsense can be viewed in "Popular Mathematics".

2 more possible rules -

• No pictures unless it is Euclidean Geometry.
• No links to Tom, Dick or Harry's website.

Colin M Davidson 62.251.121.16 20:01, 12 March 2007 (UTC)

I do tend to agree about the animations. While they do add value in explaining some points, they can also be very distracting and constantly draws the attention. The other day I removed an animation Image:Vortex-street-animation.gif from spiral only to find that it was actually a featured picture. I've been thinking about ways to present the animations without them being distraction, posibly with a sub-page or with a show/hide box. Animations also gobble up bandwidth. --Salix alba (talk) 21:53, 12 March 2007 (UTC)

Its not just pictures or animations. Popular math articles tend to accrete a varity of unhelpful, cloudy, useless statements, formulas, and templates, and not just bad pictures or websites. This is particularly true for any subject that is "hard" and has a cachet, such as Einstein's theories about spacetime, or quantum mechanics. It seems that novices wish to demonstrate thier ability and intelligence by "improving" these articls in dubious ways, garnering bragging rights by having "written" the WP article on general relativity. (Careful: this is exactly the same thing that the experts do; only that experts get fuzzy at a higher, more abstract level).

I think the Essjay/Jimbo Wales accreditation issue feeds into this. The difference is that I think the only viable mechanism is to have "stable versions": allow this wikiproject to mark a particular version of an article as "acceptable", whereas other version are caveat emptor. linas 00:55, 13 March 2007 (UTC)

"No pictures unless it is Euclidean Geometry" - are you serious ? Would you really remove the images from bifurcation diagram, elliptic curve, blancmange curve, catastrophe theory, topology, braid group, pretzel knot, crosscap, Möbius strip, Klein bottle etc. etc. ? I think these articles would be much poorer as a result. Gandalf61 13:57, 13 March 2007 (UTC)

What about this: An essentially technical article should only have illustrations that help to understand the material presented in the text. As always, such a rule should not be applied rigidly, but the tendency to add images just because it looks good, however tenuous the connection, should be countered.  --Lambiam^Talk 14:34, 13 March 2007 (UTC)

I have no idea what the original poster meant by "no pictures unless..." as that is clearly ludicrous (and also casts doubt on the rest of his statements). What you say is more reasonable, but I would be averse to such a rule at all. Is the adding of images really a problem? It seems to me there really is a lack of images, especially ones that "look good". Many math animations I've seen, such as at dunce hat (topology), have added considerably to the article. Perhaps this is all in reference to some problem I've not come across, like people adding a picture of Britney Spears holding a doughnut to solid torus. --C S (Talk) 15:33, 13 March 2007 (UTC)

I should add that my favorite example of an image whose inclusion has seemed ludicrous to more than a few but in my opinion is actually instructive is the cartoon in Bring radical. Perhaps this is more along the lines of what the OP thought was taking Wikipedia downhill. --C S (Talk) 15:40, 13 March 2007 (UTC)

2nd and last attempt to remove silly pictures.

Klein's bottle (or surface) is historically important. There should be some reference in any self respecting body of knowledge. - More so if it has lead to an interesting branch of mathematics. I am very disturbed by the "silly picture". The picture is 2nd rate (JAVA/COBOL?) and very misleading. We can only be grateful for the writer's text - something along the lines of "But don't try to do this in 3 dimensions."

Restricting pictures to Euclidean geometry is clearly extreme but it seems a better starting point than accepting anything that Tom, Dick or Harry throws into the mill.

Colin M Davidson 62.251.121.16 20:42, 15 March 2007 (UTC)

Which image specifically in the Klein bottle article do you find "silly"? I take it you don't mean the still frame from Futurama since your objection is to a computer-generated image. (How does one use COBOL to generate an image, btw?)

And what about the images is "very misleading"? That the images in the article depict immersions of a Klein bottle? The use of immersions is made rather explicit in the text and in the caption to the first image. Lunch 21:37, 15 March 2007 (UTC)

When you put quotation marks around the words "silly picture", that means either that someone called it that or that someone would call it that but you wouldn't. Yet your words make it appear that that's not what you meant. Michael Hardy 23:50, 15 March 2007 (UTC)

I'd also find it easier to understand if Colin M. Davidson would say WHICH picture he has in mind. Michael Hardy 23:56, 15 March 2007 (UTC)

I can't tell which picture Colin M. Davidson is talking about since they all look good to me. The top one is the standard image of this particular surface, looks like it was done with Mathematica, illustrates exactly the key feature of this immersion. Aside from the two other Mathematica pictures, we have a square-folding diagram, a photograph of a "real" Klein bottle, and the Futurama comic. I find the other two Mathematica pictures quite useful, though the one illustrating dissection of the Klein bottle into two Möbius strips could, I suppose, use a better angle; in particular it's nice to have alternative embeddings shown in the article since, as it is impossible to depict the surface accurately in three, let alone two dimensions, and only one picture. Really, the pictures may be the best part of the article, especially for someone interested just in an overview of the surface. Ryan Reich 00:24, 16 March 2007 (UTC)

The figure-eight one is really a little hard to follow. I can't see where the self-intersection is supposed to be. To me it just looks like a torus where someone grabbed a bit of it and turned it 180 degrees. --Trovatore 00:56, 16 March 2007 (UTC)

You might find it helpful to start with a cylinder with a figure eight base: 8 x [0, 1]. Now glue the top to the bottom but with a half-twist so that opposite parts of the eight get glued together. Also helpful to see this last part is to orient the top and bottom 8's in opposite directions. The twist makes sure the orientations match in the gluing. --C S (Talk) 01:26, 16 March 2007 (UTC)

OK, I can see it now. --Trovatore 01:35, 16 March 2007 (UTC)

From Colin M Davidson's other edits and remarks (e.g., at Talk:Dijkstra's algorithm#EWD would have cried) I deduce that he might be referring to the 'external links' of the Klein bottle article. (Indeed, they lead to one animation and one home page.) Colin, if this is correct, you could have said so from the beginning... The natural thing was to look for pictures in the article itself, since this is what your text seemed to indicate. JoergenB 20:17, 17 March 2007 (UTC)

Symbols in non-latex code

Is there a page depicting all commonly used symbols like ℤ or ∪ (not in the < math >... < / math> environment) -- and also how to type them? It always takes me an eternity to find them on other pages like union (set theory) etc. Thanks. Jakob.scholbach 16:13, 15 March 2007 (UTC)

Try User:KSmrq/Chars. —David Eppstein 16:35, 15 March 2007 (UTC)

Some are also in the edit characters below the edit box. —METS501 (talk) 20:46, 15 March 2007 (UTC)

Yeah, but wouldn't it be better to use the < math >... < / math> environment, and let the mathml convert these to the proper symbols? That way, at least one gets a uniform look-n-feel. linas 23:34, 15 March 2007 (UTC)

No, it wouldn't always be better. If we were using TeX in the normal way, it would be better. But often on Wikipedia when TeX is inline, it gets misaligned or is far too big with comical effect. Michael Hardy 23:48, 15 March 2007 (UTC)

Agreed, for Wikipedia in the present state. But hopefully the rendering of math formulas will be fixed in due time and hopefully Wikipedia will be around for a long time. So it might be better to do the right thing and expect it will look good eventually even if it looks bad right now. In other words, the problem is incorrect rendering of math formulas in the web environment; ad-hoc fixes will only make it worse in the long run. Jmath666 03:02, 16 March 2007 (UTC)

J.M.Keynes said, "In the long run, we are all dead." I think we ought to make the pages look as good as possible right now. If the graphics engine ever gets fixed, the in-line HTML will still look OK, and it will be relatively simple to cut everything over to TeX. So we can either (a) make it look OK now, and better eventually, or (b) make it look bad now, and better eventually. Which makes more sense? Think of the readers! DavidCBryant 17:03, 16 March 2007 (UTC)

CMummert for admin

I nominated one of us, CMummert, for admin. If you are familiar with his work, you can comment/vote at Wikipedia:Requests for adminship/CMummert. Oleg Alexandrov (talk) 03:16, 16 March 2007 (UTC)

Uniformization of notation at Cyclic group

New user Greg Kuperberg is giving Grubber a hard time at Talk:Cyclic group, arguing about the best notation to use in the article. It seems Greg Kuperberg wants to push for a certain notation because he uses it and it is used in some current research papers.

My understanding of wikipedia policy is that we always use the most common notation. We copy standards, we do not create them. For articles in mathematics, the most common notation is the notation used in authoritative textbooks on the subject. Perhaps someone can point me to a relevant wikipedia policy or provide some backup for Grubber. MathMartin 16:50, 16 March 2007 (UTC)

There isn't an explicit policy on math notation (but see WP:MSM). You are correct that we describe the "real world" rather than recreating it here. So if there are multiple common notations in the real world, we should just describe them, pick one to use, and get on with things. Discussion on the "best" notation tends to go around in circles. In this case, it looks like both involved parties agree that Z/nZ is acceptable. CMummert · talk 18:28, 16 March 2007 (UTC)

Uh, Kuperberg has been editing here under that name since 2004, judging by the history of his talk page. He's hardly a new user. —David Eppstein 05:07, 17 March 2007 (UTC)

Yes, he is not a new user. I should have checked more thoroughly. MathMartin 13:21, 17 March 2007 (UTC)

Hmm. There is a Greg Kuperberg who claims to have coauthored a paper with you, "Fat 4-polytopes and fatter 3-spheres". On the down side, he claims to have a doctorate in mathematics from U.C. Berkeley, which may have brutalized his sanity; and U.C. Davis has a well-known enology program, which may also have had adverse effects. Any comments on his sanity or sobriety from your experience? ;-) --KSmrq^T 06:44, 17 March 2007 (UTC)

I don't recall that I've met him in person, just corresponded electronically on that paper and other matters. I have no reason for thinking him any less sane or sober than the typical mathematician. —David Eppstein 06:49, 17 March 2007 (UTC)

Proposed deletion of "list of cycles"

See list of cycles and Wikipedia:Articles for deletion/List of cycles. Michael Hardy 22:24, 18 March 2007 (UTC)

A-class review proposal

As several editors have expressed an interest in it, I have created a proposal for an A-class review process for this project. If you are interested, please discuss it at the associated talk page. CMummert · talk 00:36, 6 March 2007 (UTC)

We now have the first article for review Addition see Wikipedia:WikiProject Mathematics/A-class rating/Addition. --Salix alba (talk) 10:14, 9 March 2007 (UTC)

I have moved the proposal to Wikipedia:WikiProject Mathematics/A-class rating. Please feel free to nominate articles! CMummert · talk 13:08, 20 March 2007 (UTC)

Rating importance calibration

We've been having a discussion on calibration of the mathematical importance rating system over on Talk:Penrose tiling that might be of more general interest to the participants here. —David Eppstein 18:40, 17 March 2007 (UTC)

Using the criteria set forth there, I am tempted to say that Limit (mathematics) has top or high importance, not the mere mid importance it has been dealt.  --Lambiam^Talk 20:11, 17 March 2007 (UTC)

I agree, as one of the foundations of calculus and many other uses, high seems to be the appropriate value. I've changed the template accordingly. --Salix alba (talk) 22:04, 17 March 2007 (UTC)

David: Your proposed criteria at Talk:Penrose tiling seem excellent at first, but I am worried about them. It seems to me that the principal criterion you have offered for judging the importance of an article is whether you would be embarassed to find that the article was not in the encyclopedia. This seems initially like a reasonable idea, particularly since your examples all elicit about the same level of embarrassment for me as you say they would for you. But I worry that not everyone will be similarly embarrassed by the same things.

If personal embarrassment is used as a criterion, and if there is a consensus about the degree to which individuals would be embarrassed by the hypothetical ommission of articles, then all is well. But I fear that using embarrassment as a criterion will only turn the vague and subjective arguments about "importance" that we have now into equally vague and subjective arguments about personal embarrassment. Nothing will have been gained, and perhaps it will be even worse, since the terms of the discussion will encourage participants to rant and flame about about their personal emotions. Consider how much worse it would be to describe the importance of an article in terms of the rage and fury you would feel if the article were omitted---it should be clear that this way of framing the issue would be unlikely to promote respectful, rational discussions. Using embarrassment as the measure, rather than of rage, would ameliorate the potential problem here, but not eliminate it, I think.

I do not have a useful alternative to offer, but I am concerned that bringing embarrassment into the official guidlines is a step in the wrong direction, and could turn out to be a grave mistake. I hope that the WP:M community can come up with something less likely to promote flame wars. -- Dominus 13:50, 19 March 2007 (UTC)

I would be happy to have a less subjective scale. But the crucial thing for me is that it should not quantify importance only with respect to current mathematics research or pedagogy, but rather importance as a part of an encyclopedia, taking a broader view of connections to nonmathematical topics as part of that quantification. —David Eppstein 15:16, 19 March 2007 (UTC)

The biography importance characteristics do attempt for something more objective bassed around the importance of the topic cross discipines, top is something like big influance over a wide range of topics, high influence on topics outside of the domain (i.e outside of mathematics), mid influence across a number of fields within the domain, and low being of interest primarially within the field. (or something to that effect) see [19]. I find a certain appeal to adapting this to suit maths articles. --Salix alba (talk) 20:16, 19 March 2007 (UTC)

E8

The E8 (mathematics) lie group hit the news today, which coverage of a full enumeration on the BBC and slashdot, see talk page for links. The article is very technical and could do with some attept to describe it in laymans terms, especially the meaning of the new result. --Salix alba (talk) 20:04, 19 March 2007 (UTC)

This could make a better movie than A Beautiful Mind; read David Vogan's narrative of the project. This site is a good starting point for other info. --KSmrq^T 22:44, 19 March 2007 (UTC)

Here's a press-release: http://web.mit.edu/newsoffice/2007/e8.html. Note that Jeffrey Adams, who, as said in that release, is the project leader, has made a Wikipedia account, at User:Jeffreyadams. Nice. Oleg Alexandrov (talk) 03:41, 20 March 2007 (UTC)

Hmmm, compsci heroics. But we need to have more on the mathematics of it. Charles Matthews 10:56, 20 March 2007 (UTC)

Attention: Probability Theory

I was browsing through the list of vital articles, and found out to my dismay that most (almost all) content has been removed from Probability theory. I have already left some comments at its talk page, but I would like additionally to alert as wide a circle of mathematics editors as possible. Arcfrk 03:25, 21 March 2007 (UTC)

Serious work has started on Probability theory. However, we need experts in probability theory and/or statistics to map out the article (urgent) and contribute high quality content (as the time permits). Arcfrk 04:10, 22 March 2007 (UTC)

Sobolev space

I would like to attempt to rewrite Sobolev space. This article, which is quite important, is written in a messy manner (in my opinion). Some points which I would like to stress are described in User:Igny/Sobolev space (they are somewhat mentioned in the article, but like I said it is a mess). In particular I would like to stress the connection to the Fourier transform of distributions, which, by the way, deserves a separate article in my opinion. I will appreciate any input from other editors, in particular a blessing to proceed. (Igny 19:17, 21 March 2007 (UTC))

Yes, the article could be better. If you undertake such project, could you please allow for multiple definitions of Sobolev spaces? Perhaps you could structure it as section "Definition of Sobolev spaces", with subsection(s) for definitions, so that more definitions can be added in future. Because:

• different definitions do not always give equivalent spaces
• simple definitions though maybe not as satisfactory have an important place in teaching and are very suitable for encyclopedic purposes. In order of accessibility:
• definition by completion of a space of smooth function (requires only the concept of completion of metric space)
• definition by $L^{p}$ weak derivative (requires Lebesgue integral but neither Fourier transform nor distributions)
• the distributions/Fourier transform way goes the whole mile but is the least accessible
• the definition by Fourier series on an interval is a good example for teaching and sometimes a nice trick to know

And yes, distributions should have their own article. So should interpolation of spaces.

Also, it would be good to have at the top of the article something simple yet specific even if maybe not 100% accurate so that people without much background get the correct idea what the topic is (i.e. without knowing what $L^{p}$ and multiindex are and so on). Many math article are done this way. Maybe something like this: Sobolev space is a normed space of functions. The norm on Sobolev space of order n involves the value of the function as well as its derivatives of order up to n. The Lebesque spaces ... are a special case of Sobolev spaces of order zero. Negative order Sobolev spaces are defined as dual spaces to spaces of positive order, and Sobolev spaces of non-integer order are defined by interpolation of normed spaces (which is not the same as interpolation of function). The importance of Sobolev spaces lies in the fact that the smoothness of a function is measured by in which Sobolev space it is, and solutions of PDEs fall naturally in Sobolev spaces." Then the example of the most common space, $H^{1}=W^{2,2}$, in 2D, with all partials written out, and saying that the derivatives are suitably generalized for this whole thing to work, then the TOC and then the messy technical stuff. Thanks for taking this up! Jmath666 01:12, 22 March 2007 (UTC)

Well, I would have to say that the draft article is not written in a very friendly style. We are constantyly asked to have more explanation for the general reader. There is also a constant pressure from experts to remove verbal explanations, replacing them by 'precise' statements and formulae. The difficulty is that articles then lose all chance of access by non-experts. It is fairly typical that an explanatory comment

The Sobolev spaces are the modern replacement for the space C1 of solutions of partial differential equations. In these spaces, we can estimate the size of the butterfly effect or, if it cannot be estimated, we can often prove that the butterfly effect is too strong to be controlled.

was removed by someone in January 2006 claiming it was 'original research'.

Charles Matthews 08:02, 22 March 2007 (UTC)

This is not a draft per se, it is a collection of elements of the future draft. I was just writing things, which the current article lacks or states poorly (again in my opinion). In anyway, I will continue working on my version (make it friendly and so on), which I hope at some moment will be good enough to replace the current version. I just want other editors know about this effort, and contribute with advice if possible. (Igny 13:22, 22 March 2007 (UTC))

Are you sure the desired improvement cannot be attained by a sequence of piecemeal edits – in general a more desirable approach?  --Lambiam^Talk 14:24, 22 March 2007 (UTC)

Yes explanatory statements for non-experts are needed but the butterfly was a bad one no matter how catchy it sounds; please see the discussion why it was removed. And indeed it was missing references. The reason why Sobolev spaces exist is simply that solutions of PDEs are in general not in the classical $C^{n}$ spaces. For example, in 2D and 3D linear elasticity, there are functions with finite deformation energy (=solutions of the elasticity equations; Nature settles to the lowest energy state) that are not bounded and so not even in $C^{0}$. One can construct such function as a special kind of spike (this makes a nice picture for the non-specialist), which also shows why point constraints make no sense in >1D, even if engineers merrily keep putting point constraints in their Finite element models all the time. Jmath666 15:21, 22 March 2007 (UTC)

Well, I know why it was removed. I don't care about the butterfly. I do care about the general principle of making things comprehensible. And citing OR about helpful heuristics, which are clearly just that and not assertions, is too much on the silly side for me. Everyone knows that some heuristics are 'folklore'. Charles Matthews 18:00, 22 March 2007 (UTC)

I agree. It is very important to make things comprehensible. I do not think the butterfly statement was helpful heuristics, though. More like an attempt to push the right buttons than to give a clue about the subject. And for me at least it sounds so specialized I would have liked a reference. Jmath666 18:25, 22 March 2007 (UTC)

I don't have time to write anything just now, but I think th first chapter of Susanne C. Brenner and L. Ridgeway Scott, "Mathematical Theory of Finite Element Methods", Springer-Verlag, 1994 (ISBN 0-387-94193-2) is a particularly nice introduction to Sobolev spaces. It ought to be accessible to anyone having had a first course in analysis at the level of, say, Rudin or Hewett and Stromberg. Greg Woodhouse 18:34, 22 March 2007 (UTC)

Cross-project help part 2: Concluding Vandalism Study 1

Hello again! Wikipedia:WikiProject_Vandalism_studies's first study is finally about finished. We loved you guys' help a few weeks ago in giving some eyeball time to how the study was composed math wise, and now that we're almost done, we're wondering if you wouldn't mind checking over the results. The study's end results themselves are here, and the discussion of what this means for the conclusions is here. We are keeping in mind that measuring is easy, but knowing what you are measuring is the hard part. Any and all comments, critiques and math angles not considered would be much, much appreciated. We want this to be as tip-top as possible before reporting our findings to the community at large. Thanks everyone. JoeSmack ^Talk 23:59, 24 March 2007 (UTC)

Attribution

I'm curious what the math community has to say about the proposed merger of several key Wikipedia principles into one: Wikipedia talk:Attribution/Community_discussion. I can't see that it really changes much about the way we do things around here, but I would like to know if there are issues to consider. (Would we have to fight battles over inline citations all over again, for example?) VectorPosse 10:02, 25 March 2007 (UTC)

User:SlimVirgin has written an explanation of why the change was proposed. My personal opinion is that the current wording of WP:ATT is better than WP:V. CMummert · talk 11:25, 25 March 2007 (UTC)

See WP:ATT#How_to_cite_and_request_a_source. We will have to watch this; it used to mandate inline citation, but the present language may be adequate to deal with the inline enforcers. One of them seems to misread it, however, here. You may want to comment on this when you !vote. Septentrionalis PMAnderson 15:16, 25 March 2007 (UTC)

Like SlimVirgin, I see WP:ATT as a needed step forward, if not a panacea. Sadly, there is a heavy thumb on the scales; see these comments by Jimbo Wales. (And, yes, I checked the edit history because his views seemed so startling I wondered if they had been spoofed!)

Perhaps next we can focus on the task of actually checking each article for correctness (and maybe a few other things, such as completeness, clarity, neutrality). Of course, it is meaningless to "certify" an article that "anyone can edit" two seconds later. [If Wikipedia is serious about becoming a trustworthy source, an obvious model is the software community, where lack of reliability can have dire consequences. FreeBSD, for example, is used by businesses that could suffer severe economic and legal harm if their operating system let them down. So, how to allow development and manage the risk? Standard practice is to offer two versions: one "stable" and one "bleeding edge". If you want (or need) to use the latest and greatest features, you may be willing to accept the risk of the experimental version. Wikipedia today gives you no choice. How can a responsible teacher point students to Wikipedia, when at any moment the geometry article, say, might look like this? (Check the edit history; this is hardly an isolated example.)] Happily, efforts are afoot to address this need, so I remain optimistic.

Meanwhile, clearing away Wikipedia's bizarre take on "verifiability" and "original research" can only be seen as a Good Thing (even if we never manage to hunt down and exterminate all members of the "inline citation squad", who insist every statement must have a footnote). --KSmrq^T 16:39, 25 March 2007 (UTC)

KSmrq deletion of other's comments

To KSmrq (talk · contribs): Since you appear to be unable to refrain from accidentally deleting the comments of other users, which you did again to Lambiam and Oleg Alexandrov recently, I suggest that you make a practice of checking the revision history after you save your edits and immediately repairing any damage you caused. JRSpriggs 12:10, 25 March 2007 (UTC)

I find it outrageous that you continue to make the daily temperature swing through such excessive ranges throughout the year, with consequent damage from floods and fires; please desist at once or take steps to correct the damage you cause.

Do I make myself clear? Your personal attack is irrational and offensive. If you want results, pressure the developers. I will be happy to work with any developer who wants to track down this issue.

I am fairly sure that the consequences of this bug are far more deleterious to me than to anyone else, and I have already publicized the problem (as you apparently know) and tried a number of changes in practice to try to work around it.

Frankly, it looks like an flaw in maintaining database integrity through multiple overlapping transactions. I don't know if you know anything about the design of database software, but this is the kind of thing that must be carefully built in and regression tested for bugs in any system that is expected to confront such complexity. It is easy to handle one "atomic" transaction at a time; it is much harder to handle multiple simultaneous transactions with unpredictable event sequencing. --KSmrq^T 15:04, 25 March 2007 (UTC)

I am not the one who is being irrational here. Nor am I asking you to do anything which I do not already do myself — I almost always check the revision history after I do an edit to be sure that I did what I meant to do. I would also point out that your edits (together with the bugs you mentioned) have caused this problem as often as all other editors on this project put together. A possible factor in causing this is that your edits are often very lengthy, providing more opportunity for edit conflicts. If you want this to happen less often, you could write your messages off-line and then cut and paste them in quickly to reduce the window for edit conflicts. JRSpriggs 05:17, 26 March 2007 (UTC)

Can you take further discussion of this issue to the user talk space?  --Lambiam^Talk 07:08, 26 March 2007 (UTC)

Academic paper on Wikipedia

I see a reference in Wikipedia:Wikipedia Signpost/Newsroom/Suggestions#Academic paper on Wikipedia to a research paper "Assessing the value of cooperation in Wikipedia" by Dennis M. Wilkinson and Bernardo A. Huberman.[20]. The paper finds that article quality is correlated with both number of edits and number of distinct editors. Is it just me, or is some of the mathematics and statistical techniques a bit off?  --Lambiam^Talk 14:05, 26 March 2007 (UTC)

Welcome template for mathematics

The recent welcoming of a new mathematics editor led me to wonder, what would be most helpful to tell a newbie to our mathematics community? Information could go in a new mathematics-welcome template, or on the project page, or both. So, aside from the usual Wikipedia welcome, what might we say?

In particular, what did you find most helpful? Most difficult to discover? What do you find yourself wishing most new editors would do or avoid doing with regard to mathematics articles (that we can teach)? Other comments?

To lead off:

• In the difficult discovery category, I would hate to go back to life without popups (with popupRevertSummaryPrompt=true); the ability to hover over a linked technical term and see its lead paragraph is an incredible timesaver.
• The Help:Formula page is essential, showing the parts of TeX supported by the MediaWiki texvc software. I also found it handy to have my own page of characters; but newbies need help configuring their system to display them all.
• We should continue to expand the reference resources page; I'd love to see a wiki version of a BibTeX-style database across mathematics articles (perhaps bot-assisted).
• Newbies often need illustration assistance; we could be more helpful than Wikipedia:How to create graphs for Wikipedia articles. (A recurring example: commutative diagrams.)
• Beyond WP:MSM, I have suggested some writing tips that I wish were more widely followed.

Our target audience will include a gamut from professional mathematicians to young students; each needs to be told different things (for the former, Wikipedia is not a technical journal; for the latter, there is more to mathematics than you have seen). A good orientation could bring rich rewards. --KSmrq^T 06:22, 17 March 2007 (UTC)

This sounds a great idea. --Salix alba (talk) 09:07, 17 March 2007 (UTC)

I am in complete agreement. If I had to choose a list of resources that took me a while to find, those that would have been helpful from the start, I would have listed exactly the resouces KSmrq has proposed above. VectorPosse 10:02, 17 March 2007 (UTC)

One more quick note. I might recommend that the math welcome be constructed in such a way that it supplement the normal welcome template instead of replacing it. (Actually, this is probably what KSmrq already has in mind.) It is likely that the math-specific editors we're targeting will have already received the standard welcome. Besides, the regular welcome has important general Wikipedia info that is indispensable. VectorPosse 10:08, 17 March 2007 (UTC)

I would suggest making a subpage of WP:WPM with resources for new editors, and then making the talk page message a welcome with a pointer to the subpage. Then we could also link to the subpage from WP:WPM and refer to it ourselves as a resource. CMummert · talk 18:28, 17 March 2007 (UTC)

I'd call it something like "Editor resources for mathematics articles", without the word "new", since they are also useful to seasoned editors. As far as I'm concerned KSmrq's buried essay, with a bit more structuring and emphasis on an editor's problems when writing a mathematics article, can be made into one of these resources.  --Lambiam^Talk 19:56, 17 March 2007 (UTC)

So anybody actually willing to create it? :) Oleg Alexandrov (talk) 03:37, 18 March 2007 (UTC)

Yes, I will begin soon if no one beats me to it.

Some questions:

1. Are we agreed to accumulate the resources on a subpage of the project, and to make our template a minimal augmentation of the standard welcome template?
2. Any other must-have items?
3. Perhaps we should use the "Resources" subpage for this, moving its current contents to "Reference resources".
4. Apropos of which, can our bot-master whip up something to go through the mathematics pages and collect all the references, so that we can begin to massage them into a coherent database? Lazily, I envision beginning with a simple accumulation of exactly what appears in each article, then sorting like entries together, then eliminating duplicates and converting each entry to a standard form, then filling in missing information like ISBN-13, then checking each entry and marking it as confirmed correct (with respect to the data in the entry, without regard to the use of the citation), then taking over the world. This is obviously a naive strategy that may be overwhelmed by size, but it is otherwise easy and incremental. Or perhaps something better already exists of which I am unaware? Or is the consensus that this is a crazy idea that only a fool would undertake?

Continuing suggestions still welcome, of course! --KSmrq^T 09:20, 19 March 2007 (UTC)

I will start a thread below on the fourth bullet; it wouldn't fit here. CMummert · talk 12:13, 19 March 2007 (UTC)

One thing to point to is Wikipedia:WikiProject Mathematics/Participants. Not everyone finds their way there. For example CMummert — unaware or just shy? Paul August ☎ 05:21, 19 March 2007 (UTC)

One was created a couple months ago: User:C S/welcome. I didn't like it much though, which is why I haven't really used it. Perhaps having something concrete to critique will help. --C S (Talk) 05:40, 19 March 2007 (UTC)

I put something online at Wikipedia:WikiProject Mathematics/Editor resources. Everyone should feel free to add or remove things or criticize what is there. CMummert · talk 13:00, 19 March 2007 (UTC)

Extracting references from articles

Extracting references from articles is not trivial. It would be relatively easy to get a list of all the instances of {{cite book}} and friends. It would be much harder to automatically deal with hand-formatted references. I could get the contents of every "References" section (there are about 4500 of them), but it would take a lot of massaging. I'm not sure what plan you have in mind for the information. But anyway, I started the program to update my cache of math articles, which is going to take about 12 hours. I can extract whatever data is requested. CMummert · talk 12:13, 19 March 2007 (UTC)

Interest?

A while back I started writing Wikipedia:WikiProject Mathematics/Editor resources. Is there still interest in this sort of page? It would not be difficult to write Template:maths welcome to point to it. CMummert · talk 11:35, 29 March 2007 (UTC)

Ah, I was looking for that page the day before yesterday but I forgot why I was looking for it before I had found it. The "Editor resources" is very useful to point editors to. I hardly use welcome template myself (information overload) so I'm not really interested in that. -- Jitse Niesen (talk) 12:40, 29 March 2007 (UTC)

Although WP:WPM has an info box mentioning "Editor Resources", it does not link to WP:WPMER.  --Lambiam^Talk 14:11, 29 March 2007 (UTC)

Citizendium content

Citizendium is now live, and I thought I'd spend a few moments looking at their mathematics.

[21] is an article about Kummer surfaces, and is more detailed than what we say by quite some way. It is marked GFDL, so let's assume there is no problem in principle if we wanted to import it.

The problem in practice is that one wants to import the wikified content, but to 'edit' (get the marked-up version) one needs an account, and there are procedures for that (real name, CV, etc.). My question is: does anyone in this WikiProject already have an account? Would anyone actually want to create an account for the purposes of importing material here? Charles Matthews 20:49, 26 March 2007 (UTC)

http://en.citizendium.org/wiki/User:Oleg_Alexandrov --Pjacobi 21:16, 26 March 2007 (UTC)

http://en.citizendium.org/wiki/User:Mark_Jason_Dominus --Dominus 22:54, 26 March 2007 (UTC)

Caution. I can't tell what the copyright status of that article is; the notice at the bottom is not clear about how to determine it. It might be better to wait until CZ gets their act together before we start copying from them. I think I have seen comment by Sanger where he suggests that their "to be determined" license may be incompatible with GFDL, and it would be a pain to revert articles because of "contamination". There are some active discussions about licensing at the CZ forums. CMummert · talk 21:22, 26 March 2007 (UTC)

I agree with CMummert. Let's wait with the copying of material. —METS501 (talk) 21:24, 26 March 2007 (UTC)

Here is a quote from the CZ forum that reinforces what I was saying: "We should not underestimate the potential ills resulting from WP's ability to take CZ content." [22] I don't know that such opinions are representative, but the quote points out the need for caution. CMummert · talk 21:28, 26 March 2007 (UTC)

The current position at Citizendium is summed up by "We are definitely undecided (about the license)". They'll use GFDL for articles derived from Wikipedia, and either cc-by-sa or cc-by-nc for home-grown articles. These are Creative Commons licenses; cc-by-sa is similar to GFDL and would probably allow us to copy their articles; cc-by-nc differs in not allowing commercial redistribution, and thus that would prohibit copying their articles. So, yes, we better wait with copying their stuff. By the way, I also have an account there. -- Jitse Niesen (talk) 00:56, 27 March 2007 (UTC)

Is it OK to link to their articles from ours as we might with MathWorld? JRSpriggs 07:16, 27 March 2007 (UTC)

Personally, I can't see why we can't link to them as a reference or external link. CMummert · talk 12:14, 27 March 2007 (UTC)

Certainly we can link. I have no objection if this new source is treated as just another web site, but perhaps we should allow them to establish credibility before we genuflect. Consider MathWorld, one of the early sources for broad mathematical information on the Web; we have learned over time to be cautious in relying on content there. --KSmrq^T 14:25, 27 March 2007 (UTC)

Yeah, let's hope that their licence won't be incompatible with GFDL. I assumed that they wanted to differentiate themselves by having a "better"/different way of doing collaborative editing than Wikipedia, such an attempt is of course laudable, whether it turns out to work or not. Making content transfer a one-way street however, would make it harder to decide later whether they were successful because they had a better model or because they were able to take advantage of Wikipedia content without giving anything back. Oleg Alexandrov (talk) 15:15, 27 March 2007 (UTC)

I don't quite follow. How can they use WP content and then license it under an incompatible license? Doesn't GFDL forbid that? --Trovatore 15:20, 27 March 2007 (UTC)

They can't; it's the material that originates at CZ that they haven't decided how to license. They decided a while back not to take everything from WP, but only take articles when someone will immediately edit them. Some editors will just start from scratch. CZ has a way of marking which articles contain WP content, but I don't know that it's very accurate yet.

This is all a matter of copyright, not intellectual priority. If a CZ article covers something that the corresponding WP article doesn't, we are free to write our own material about it so long as ours is sufficiently different than theirs, regardless of copyright. This is no different than the situation with Brittanica, which has no sort of open copyright. So I find the idea that a closed license will prevent us from using their material to be misleading. CMummert · talk 15:45, 27 March 2007 (UTC)

Heh. It is much easier to write an article by doing a copy and paste from somewhere and going from there, then starting from scratch, even with good references. So I'd think it does matter if their license is compatible with GFDL. Now, the people at Citizendum seem concerned that free sharing would be more advantageous to Wikipedia than to them. I'd doubt that. For example, we've been borrowing a lot from Planetmath, and they copy stuff from us sometimes too, and that benefited both sides and disadvantaged nobody. Anyway, it will be fun to see if Citizendium turns out successful. Oleg Alexandrov (talk) 03:06, 28 March 2007 (UTC)

Work on probability theory

I have added a Classification section to the probability theory, your comments/updates on it will be useful. To me it also seems that major portion of the article needs extensive copy editing... I am gonna propose this as a candidate for collaboration of the week. Cheers --Hirak 99 15:59, 28 March 2007 (UTC)

hm, would most probabilitists agree that one can "classify" in this way? seems kinda unlikely. i would recommend folks take a look. Mct mht 19:49, 28 March 2007 (UTC)

Geometric Median

I've created an article on Geometric median, please feel free to improve by adding more information in your free time. Is there a formal way to request for a diagram? Cheers --Hirak 99 16:03, 28 March 2007 (UTC)

It's not formal, but you could leave a request on Wikipedia talk:WikiProject Mathematics/Graphics. By the way, if geometric median is unique, and 1-dimensional median is a special case, then it is also unique, quod non. Same problem in higher dimensions for a set of collinear points of even cardinality, with the empty point set as an obvious case.  --Lambiam^Talk 08:02, 29 March 2007 (UTC)

Thanks, updated the uniqueness portion in the article. --Hirak 99 10:17, 29 March 2007 (UTC)

Corollary

I noticed recently that corollary is a redirect page to theorem. I thought someone here might want to make a proper article out of it.--Jersey Devil 01:15, 29 March 2007 (UTC)

• It could be an attempt at humour, similar to the tired old joke of making Self-reference redirect to itself. Terry 02:04, 29 March 2007 (UTC)

I cleaned up Theorem a little a long time ago. The main difficulty is finding any sort of canonical reference for the terminology, in order to get the articles to be more than dictdefs.

Personally, I think it would be useful to make a single article "Theorem, Lemma, and Corollary" that discusses these terms. It would also be nice to do something with Mathematical terminology. But then, a lot of things would be nice.

Here is a quick summary of the various articles on mathematical terminology:

• Theorem is start-class
• Conjecture is B-class
• Axiom is B-class
• Lemma (mathematics) is a dictdef
• Corollary redirects to Theorem
• Rule is a disambig page pointing to Axiom and Theorem
• Actual articles, but only tangentially related to math: Principle, Law, Hypothesis
• Other articles: Mathematics as a language, Mathematical terminology, Terminology (mathematics)

CMummert · talk 02:13, 29 March 2007 (UTC)

Mathematics now a featured article candidate

Mathematics has been made a featured article candidate.  --Lambiam^Talk 07:37, 29 March 2007 (UTC)

Disambiguation for M23, M24, and a few other numbers

A couple of Mathieu groups are listed on a few disambiguation pages that I have edited or will edit soon (e.g. M23, M24). The description of these number given at Mathieu group is incomprehensible to the average person. (Note that I have a Ph.D. in astronomy.) Could someone leave a short (one sentence) description of what these numbers are supposed to be on my talk page so that I can write reasonable entries for these numbers on the disambiguation pages? Thank you, Dr. Submillimeter 10:50, 30 March 2007 (UTC)

The description given at Mathieu group might not have much meaning if you do not know what a group is, but it pretty clearly says that M23, etc. are groups, and doesn't at all suggest that they are numbers. The entry already at M24 seems fairly reasonable to me - a disambiguation page is not the place to have long explanations. It could be reworded to "M₂₄, a Mathieu group (a type of mathematical object)" or something like that. JPD (talk) 11:07, 30 March 2007 (UTC)

Thank you. I will try working with this, although something in even simpler terms would be better. Also, is it possible to write an introductory paragraph to Mathieu group that explains the concept in less technical terms? Dr. Submillimeter 11:28, 30 March 2007 (UTC)

It might be worth trying to get a less technical introduction in the article, but I'm not sure what you mean by simpler terms for the disambiguation. "M₂₄, a Mathieu group"/"the Mathieu group M₂₄" simply tells you its name(s) and provides the link, and "mathematical object" is the simplest way to describe what sort of thing it is. Anything more would either be more technical or would become the sort of long explanation that doesn't belong on a disambiguation page. JPD (talk) 11:43, 30 March 2007 (UTC)

What you have suggested may be the best that can be done for disambiguation pages. It would just be nice for the average reader to understand what it is if they come across the disambiguation pages. That may not be possible, so just "M24, a type of mathematical object called a Mathieu group" may be the only realistic solution. (I hope I have not caused any offense.) Dr. Submillimeter 12:14, 30 March 2007 (UTC)

I had a go at writing a standard dab for the five Mathieu groups. Geometry guy 15:02, 30 March 2007 (UTC)

I made some minor stylistic changes (removing parentheses and periods), but I will otherwise use Geometry guy's dab text. Thank you, Dr. Submillimeter 15:09, 30 March 2007 (UTC)

Yes, that's much better, but it's not going to be possible to give people an idea of what they are unless they already know some group theory, any more than a dab page should explain what a lenticular galaxy or Taoiseach is. JPD (talk) 15:26, 30 March 2007 (UTC)

But hopefully they would be defined sufficiently precise to disambiguate them from other entities sharing a moniker with lenticular galaxies and the Taoiseach. And it is really not much effort to write: [can refer to:] "the Taoiseach, the leader of the Irish cabinet". It may save the reader a click, because that may be just all they needed to know.  --Lambiam^Talk 13:54, 31 March 2007 (UTC)

I would consider reorganising the first and second paragraphs. To a layman the most interesting thing about them is that they are some of the exceptional cases in the classification of finite simple groups. Once the motivation for why these are objects worth study the reader might be encouraged the to read the more technical details. --Salix alba (talk) 20:21, 31 March 2007 (UTC)

Addition to the math style manual

Well, I see good agreements above that something needs to be said in the math style manual about this issue. I started a section, Wikipedia:Manual of Style (mathematics)#Choice of fonts. It is just an initial write-up, which I hope reflects the sentiment above. Changes to it and comments here on it are very welcome. Oleg Alexandrov (talk) 15:20, 24 March 2007 (UTC)

There is a certain amount of overlap with the subsubsection Font formatting, which is a bit confused as to whether it is about markup or about typesetting conventions.  --Lambiam^Talk 18:37, 24 March 2007 (UTC)

Italic Greek letters

The principal discussions of this have been whether to use italics on Greek names; for example in the article Constantinople. There has been agreement not to do that, because

• the Greek text already stands out from running Roman text,
• our Greek italic font isn't very good, and the bold Greek is worse.

I'm not sure how much this should apply to mathematics; but I see no reason to use α (''α''), when α works fine. Septentrionalis PMAnderson 15:39, 24 March 2007 (UTC)

This is another place where I would like to see flexibility and not policy. Any guidance on the use of fonts for Greek names simply does not apply to mathematics, any more than the use of Roman letters for Roman names implies mathematical variables should be in Roman. I actually think the italic Greek letters look better for variables and they more closely resemble the TeX form (for similar reasons, I tend to use \varphi and \varepsilon rather than \phi and \epsilon in TeX - but \theta rather than \vartheta). Also I sometimes find it helpful to distinguish π (a number celebrated on 14th March in the US and 22nd July in the UK :-) ) from π (e.g., a bundle projection in geometry and topology). Geometry guy 18:48, 24 March 2007 (UTC)

To my surprise, I discovered that the current Manual of Style is rather prescriptive on this point. I searched for some previous discussions, but found nothing. So for the moment, I will edit the MoS to make it less emphatic (excuse the pun). If someone wants to continue this discussion in a new section, I will be happy to contribute! Geometry guy 18:37, 30 March 2007 (UTC)

Apr 2007

Upright d in math notation

An anon has been going through articles replacing italic d with upright d in math articles, for example

${\frac {df}{dx}}$

to

${\frac {{\mathrm {d} }f}{{\mathrm {d} }x}}.$

There is a small discussion about this at talk:Derivative.

As pointed out by Geometry guy, the previous discussion about this at Wikipedia talk:WikiProject Mathematics/Archive 4#straight or italic d? did not achieve consensus on what to use.

However, I would argue that while people should be allowed to use whatever notation they choose, I believe it is not a good idea to do mass changes to articles which used one type of notation for a long time.

That is to say, the vast majority of Wikipedia articles (all articles that I am aware of) use italic d notation. I vote to revert the anon conversions and to go back to status quo italic d notation at derivative and differential form. And if somebody starts a new article, and want to use roman d, they should be allowed. Comments? Oleg Alexandrov (talk) 15:00, 23 March 2007 (UTC)

I agree. Paul August ☎ 15:40, 23 March 2007 (UTC)

As do I. (Of course, I also think that the non-italicized d is wrong, but that's another story.) there are a lot of areas in mathematics where there are variations in notational style, and it seems a lot of energy gets spent on discussions about which one is right. However, within a single article, I think we should try to be consistent, if possible. Greg Woodhouse 15:46, 23 March 2007 (UTC)

The archived discussion on d vs. d is not so good, but there was a really intense argument over i vs. i for the imaginary unit linked there. I will paste their summary of the resulting accord:

Summary of reasons

Reasons for pro italic usage of imaginary unit in Wikipedia: i
most mathematics books/papers use italic notation of imag. unit
italic notation of imag. unit looks better Oleg Alexandrov
is a conceptual case of definition, italic i is needed Septentrionalis
Reasons for pro non-italic usage of imaginary unit in Wikipedia: i
Better semantics. This has several beneficial implications. PizzaMargherita
prevents confusion with running index i, electr. current, etc. Wurzel
offers electrical engineering technicians an imaginary unit notation which has no interference with neither (Maxwell's) current density j nor with electr. current i Wurzel
allows parallel usage with running indexes i,j Wurzel
improves readability of formulas containing the imag. unit i because of no overlapping definitions Wurzel
i is easily acessible on many computers/text systems / fonts Wurzel
Reasons for usage of \imath
Is an alternative offered by TeX Michael Hardy

Looks to me like the arguments for italics are: "it's convention" and "I like it" (the third one is not generally applicable). The arguments against are "better semantics" and numerous practical advantages, though anything mentioning current is irrelevant to mathematics and the one about being more accessible for many systems is irrelevant on Wikipedia. The decision was then made to keep i because it was the existing practice on Wikipedia, although there was no consensus.

Basically, italics won because we have a commitment to: (a) following widespread standards in the non-Wikipedia literature, and (b) when this is ambiguous, giving preference to existing standards on Wikipedia. Basically the same sorts of arguments work for d vs. d and the outcome is that the former is more common and the latter is better in every way except for being less convenient in LaTeX, so we stick with d since we already use it. I support the decision, though there's a good chance that one of these days I'll write something of my own when I'm in a mood to be pedantic and Romanize all my operators and symbolic constants, because that's how I am sometimes.

However, I think the single most influential reason people really hate these notational crusades is that everyone resents the use of a notation they don't personally endorse but they learn to tolerate it with a little rolling of the eyes, until someone rubs salt in the wound by unilaterally imposing their notation on Wikipedia. For this particular reason, I would say that even though we should use really clever, unambiguous notation as mathematicians, the use of this particular, slightly ambiguous notation has been suffered for decades if not centuries and we've learned to work around it. This can be done with a minimum of effort, such as paying attention to good choice of notation (which we should already be doing) and therefore the "practical advantages" of changing the italics to roman are pretty irrelevant, and far less than the practical disadvantages resulting from various bad feelings and revert wars that might ensue from doing so.

So I'd go further than agreeing to keep d. I would say that any time someone decides to make any sort of minor but widespread notational "improvements" they should be reverted with no more than a comment here to let people know what happened. The discussion itself is foregone and, as I've argued, more trouble than it's worth. Hell, by now it's standard practice :) Ryan Reich 16:07, 23 March 2007 (UTC)

Indeed. Both d and d are acceptable, both have advantages and disadvantages. We aren't going to ever have consensus to use just one of these, so we should follow Wikipedia:Manual_of_Style#National_varieties_of_English and allow the first major contributor to decide these style variants (which should then be consistent within each article). Changing all "d"'s to "d"'s in articles where one is not editing actively otherwise is like changing all instances of "colour" to "color" or vice versa, which is a blockable offense. Kusma (talk) 16:21, 23 March 2007 (UTC)

As an apology for causing trouble by partially supporting the anon, I promised to collect some links to previous discussions, to avoid (if possible) going over the same old ground. This is what I found so far: please add to this list if you find others. I tend to agree with User:Toby Bartels (although I am from the UK and he is from the US, we both personally prefer upright d's, but oppose the math project having a policy on this - see my comments after the list). Geometry guy 16:41, 23 March 2007 (UTC)

• Wikipedia talk:WikiProject Mathematics/Archive 20#Symbol for differential (User:KSmrq makes a particularly thorough comment.)
• Wikipedia_talk:WikiProject_Mathematics/Conventions#Italic_constants
• Wikipedia talk:WikiProject Mathematics/Archive 4#straight or italic d?
• Wikipedia_talk:WikiProject_Mathematics/Archive_3#Upright_differential_operators
• Wikipedia_talk:WikiProject_Mathematics/Archive_1#Differential_d (Only User:Toby Bartels comments here.)

I am not convinced we need a policy on this. Has there been an edit war over this issue? Clearly if (as discussed before) one user makes 75 large edits in one day changing italic to roman or vice versa in many articles, these edits will be reverted and few will argue. I like diversity in wikipedia and such an edit damages this. However, sometimes a mass change in one article is not a bad thing and can increase diversity. I don't think it is a good thing if "the vast majority of Wikipedia articles... use italic d notation". Also, one of the great things about wikipedia is that it is dynamic. I don't like the idea of setting the original notation in stone, although there are of course cases where this is entirely justified, so that (for example) related articles evolve with similar notation. However, no one is going to get confused if one article with an italic d links to another with roman one, are they?

I, for one, frequently make minor edits of a repetetive nature when I contribute to an article: for instance I often italicize Greek letters in wiki-text so that they look more like their TeX counterparts. Am I right? There are pros and cons, but I would be sorry to see a policy on this, or to find my edits systematically reverted because the original contributor didn't use italic Greek letters.

As regards this particular issue, I sometimes replace an italic d by a roman d when it is clearly the exterior derivative (an operator) and not part of a "diphthong". I have no problem with another user reverting this, but I would not like it to happen systematically as a matter of policy. This is maths, not bureaucracy! In terms of the recent reverts, I would therefore like differential form to retain an upright d, and may one day give exterior derivative the same treatment. There is possibly a case for a policy for this particular usage, and I'm not sure it has been discussed separately before. Comments anyone?

I also think there is no harm in keeping the change to derivative, as this article needs a shake-up. Maybe the next editor who substantially improves this article should decide? If I were proposing a policy (and I'm not), that's the kind of suggestion I would make!

Finally, appearance (just so you know all the prejudices which inform my comments!): my view is that dx looks better as wiki-text, but for display math, the roman font renders so poorly that the case is not clear. Geometry guy 16:41, 23 March 2007 (UTC)

It is kind of unclear to me how notation change to dx from dx would cause a beneficial shake-up at derivative. Anyhow, I guess we all agree (including Geometry guy) that mass notation changes are not a good idea. And I do agree that officially codifying dx over dx or vise versa is not necessary. Oleg Alexandrov (talk) 02:56, 24 March 2007 (UTC)

Without falling into the loathsome practice of codifying, we could point out that (a) Wikipedia follows common conventions; (b) in mathematics (but not necessarily physics) italic d (and i and e) are the usual convention, at least for dy/dx and ∫y dx, in spite of ISO 31/XI and the recognized advantages of upright boldness; and (c) making mass changes of notation without discussion and consensus is not the way to go about it. The Manual of Style for mathematics already contains formulations like "Which method you choose is entirely up to you, but in order to keep with convention, we recommend ..." and "Either form is acceptable, but do not change one form to the other in other people's writing". I think that also here shedding some light on the issues for editors who are seeking guidance in this matter is only beneficial.  --Lambiam^Talk 09:38, 24 March 2007 (UTC)

Where did you see this in ISO 31/XI ? I only found this paper which states that, according to ISO 31/XI, the operator of differentiation should be set in roman type (as well as constants, i and e). pom 11:39, 24 March 2007 (UTC)

I didn't mean to suggest anything different.  --Lambiam^Talk 14:34, 24 March 2007 (UTC)

A non-mathematician's take. This has some similarities to the discussions of changing standard English spelling ('thru' for 'through' etc.). Let's face it: Convention matters, in life, dictionaries, grammar, & on Wiki. The law is made up of such conventions (driving on one side of the road, rather the other in a given country, etc.). What matters is not necessarily what convention is selected but that there is a convention for reaching agreement, so that expectations are satisfied, reducing the cost of communication. Of course conventions can change, which Wiki can reflect as necessary. So far as the math community is concerned, it would be misleading to portray notation that is non-standard as standard, which is what one expects in an encyclopedia, akin to no original research. But I like the flexibility shown above by the conventionalists in existing vs. new articles. --Thomasmeeks 12:46, 24 March 2007 (UTC)

Conventions operate in a context. What is convenient and clear in one context may be awkward and confusing in another. We are flexible with mathematical notation because we must be. As mentioned above, I have previously posted at length detailing a wide assortment of mathematical contexts for dx and friends. If, as I perceive it, we do have a consensus against any mass conversion or "standardization" compaign, then: (1) we may wish to put a note on our conventions page, and (2) revert without debate and leave a note on the editor's talk page informing them of said consensus.

I need to ask about two other notations mentioned, italic Greek letters and the square root of −1.

1. Long ago (in wiki time) I saw an admonition somewhere to not italicize Greek variables inline, or so I remember. Thus I have used, say, "θ" (&theta;) instead of "θ" (''&theta;''). Maybe it was an issue of font availability, maybe times have changed, or maybe I remember wrong. What say ye?
2. Perhaps because of long exposure to quaternions and Clifford algebras and the like, I use upright bold for our little friend i, and when only a few instances exist in an article I may inflict my preference on existing material. (See Cayley transform, for example, which I recently gave a major facelift.) I have been unaware of any consensus, and strongly prefer the bold convention for most things I create. However, in topics of complex analysis, say, it could be a serious pain to use anything other than TeX's default italic, and I would not dream of changing or complaining about i there. Except, as a matter of reader friendliness, I do object to using i as both an index and a special constant. Never would I use upright "i" without boldface. Any strong feelings?

As always, I see our role as being a bridge between a diversity of common mathematical practice and the needs of our readers, while making editing less onerous. In that regard, I note that despite our thousands of mathematics pages, the developers have not yet switched to blahtex instead of texvc, not for its much broader TeX compliance in producing PNGs, and certainly not for MathML output. I suppose I have been biding my time until the STIX fonts release (currently anticipated for April), but come that day I would like us to begin serious lobbying. To produce attractive, consistent mathematics notation by using <math> markup everywhere — that would be a great benefit for editors and readers alike. --KSmrq^T 15:26, 24 March 2007 (UTC)

I agree with KSmrq. Imposing even a "usual" usage for imaginary units is even worse that doing it for d, since it affects a much broader range of contexts. In some contexts it is entirely familiar to use i for the square root of -1, even when it is simultaneously an index. In other contexts, much greater clarity is obtained by using a different notation, and there are plenty of options: i, i, i, $\imath$, ${\boldsymbol {i}}$ and $\mathrm {i} \,$ being a few that I have seen. Geometry guy 19:15, 24 March 2007 (UTC)

It is generally the best idea to use the italics one when dealing with the imaginary unit because that is the way most textbooks do it. It is the same with the ƒ(x) vs. f(x) argument, most textbooks use italics for it. The engineering books I've seen have all used non-italics for their variables so we can either: switch all the 'i's in the context of imaginary units to italics and all the ones representing resistance with regular face 'i's; or just use an italic 'i' as the standard, unless it would cause confusion in context with electrical engineering. The Roc 1217 21:43, 2 April 2007 (UTC)

Wikipedia:Mathematics Collaboration of the Week

Wikipedia:Mathematics Collaboration of the Week has just been marked as inactive, its not received much activity since November. Should anything be done to revive the collaboration? --Salix alba (talk) 07:34, 28 March 2007 (UTC)

The knack would be to nominate things people actually want to work on ... this idea has not ever really got off the ground. It's not really adequate to say "I decide, you write, that's what I mean by collaboration". On the whole a more elitist approach might be more welcome. (I mean it might work better, not that it is more desirable.) Charles Matthews 19:16, 30 March 2007 (UTC)

I agree. I also have another suggestion. I think it would be more productive to place the emphasis on producing A-class articles rather than FA-standard. I realise the distinction is slight, but it seems that FAC can be a rather dispiriting and bureaucratic experience of dotting every i and crossing every t in the definition of a "perfect wikipedia article" (it will be interesting to see what happens to mathematics), not to mention adding inline citations for everything, which do more to damage the readability of an article than enhance its authority. Instead with A-class, WikiProject Mathematics sets the standard and places the goals, and we can enthusiastically concentrate on the things we really care about in a mathematics article: its readability, liveliness, accessibility, depth and breadth and interest of its mathematical content. I also think that the number of A-class articles is an excellent way to judge the project's success. Geometry guy 11:11, 31 March 2007 (UTC)

I don't know whether it can be (re)vived, but if it can, it needs someone who is on top of this to coordinate the process, and it would help if that coordinator is one of our several well-known and respected contributors. As far as I'm concerned the coordinated effort could also be to raise the quality of a painfully embarrassing article to above the embarrassment threshold, or in general anything, as long as there is a potential and promise of a real improvement. Personally I'd really like to see the "entry level" articles improved, the ones must likely to be consulted by mathematically relatively unsophisticated readers, but others may be more inspired by advanced topics. A crucial aspect is the process by which each time the next "Collaboration of the <TIME PERIOD>" is selected. The coordinator could perhaps each time select a few improvable articles as candidates for something like a run-off vote, and announce the selected candidates on this page. "Voting" for a candidate would signify: "I'm willing to work on this". Sometimes it also makes sense to deal with a group of related articles together.

For the process, I think the collaboration can be facilitated if we proceed by a few distinguishable phases. Phase 1 would be similar to a peer review, in which everyone can propose improvements, but also identify what the problems with the current version are, whether they have ideas or suggestions for fixing them or not. This first phase is not discussion-oriented. In phase 2, we attempt to reach consensus on the target: what are (and what are not) problems and what is the approach to be taken for improvement. Phase 3 is the implementation of the consensus reached. Each phase could last like a week. Once this process is going well, we could consider a three-article pipeline with staggered phases, so while article n is in the implementation phase, article n+2 is in the peer-review phase.  --Lambiam^Talk 12:46, 31 March 2007 (UTC)

I think a good approach would be to start with the Requested Articles page and try to get some impression of priorities there. I'd be looking for articles such as Lefschetz duality, for example (associated with one of the greats of topology, builds on Poincaré duality). In terms of grand strategy, I say it is more important to bring coverage up to date (i.e. fill in late twentieth century mathematics, at least in outline) than to worry about 'featured article' style requirements right now. (I can't imagine what group theory would look like as a FA; a comprehensive article on groups? What does that mean? It is long ago that there could be a comprehensive book on groups.) Putting it another way, there is plenty of online material on current developments, but WP should be putting in place the essential stuff which means it becomes more easily readable.Charles Matthews 11:44, 1 April 2007 (UTC)

Sines and cosines of sums of infinitely many terms

I just added this paragraph to the list of trigonometric identities, and maybe someone can add some information in response to the questions below.

---

$\sin \left(\sum _{i=1}^{\infty }\theta _{i}\right)=\sum _{\mathrm {odd} \ k\geq 1}(-1)^{(k-1)/2}\sum _{|A|=k}\prod _{i\in A}\sin \theta _{i}\prod _{i\not \in A}\cos \theta _{i}$

$\cos \left(\sum _{i=1}^{\infty }\theta _{i}\right)=\sum _{\mathrm {even} \ k\geq 0}(-1)^{k/2}\sum _{|A|=k}\prod _{i\in A}\sin \theta _{i}\prod _{i\not \in A}\cos \theta _{i}$

where "|A| = k" means the index A runs through the set of all subsets of size k of the set { 1, 2, 3, ... }.

In these two identities an asymmetry appears that is not seen in the case of sums of finitely many terms: in each product, there are only finitely many sine factors and cofinitely many cosine factors.

---

• Is absolute convergence strong enough to entail the identities, and is convergence on the right side also then absolute?
• How much can such a hypothesis be weakened, and at how much cost in weakened conclusions?

I derived the identities from scratch without careful attention to these questions (that's quite easy, as you'll see if you try it), then I found them in a couple of old books (19th-century trigonometry texts were quite detailed and thorough), but again without careful attention to what the books said about these questions. --- Lazily... Michael Hardy 02:41, 2 April 2007 (UTC)

Should not the exponent of -1 in the first equation be (k-1)/2 rather than (k+1)/2? So that the first term is positive? JRSpriggs 10:38, 2 April 2007 (UTC)

Oh. Yes. Clumsy of me.... Michael Hardy 19:56, 2 April 2007 (UTC)

...and now I've fixed it in what I wrote above, lest rely on it. Michael Hardy 19:57, 2 April 2007 (UTC)

In mathematics

We quite often begin our articles with "In mathematics..." or something similar. This has been discussed previously at Wikipedia_talk:WikiProject_Mathematics and I'm happy to report that the consensus was to support a variety of styles. :)

Anyway, I just wanted to draw attention to a variant which I have started using, which I think might be quite useful to other editors (who also might have their own variants which they would like to share here). Quite often it is necessary and appropriate to set a more precise context in the first sentence, such as "In analysis...". Sometimes it is safe to do this without the risk that the reader will assume the article needs psychotherapy, sometimes not. In the latter case, mathematics needs to be mentioned. In this particular example the problem is solved easily by linking directly as "In mathematical analysis...", but it is not always so easy to find an elegant solution. A common approach (which I have used), is to begin "In mathematics, more specifically in widget theory...", but I am increasingly finding this rather awkward, so I came up with an alternative

In the mathematical field of widget theory...

This is a bit shorter and seems less forbidding to me, so I thought I would share it here. Comments and suggestions very welcome! Geometry guy 18:29, 30 March 2007 (UTC)

I think the main issue is the very quick orientation of the uninformed reader. "In mathematics ..." is very good for that; "In geometry ..." is OK. Anything else risks drawing people further into the article than they personally need. The lead section of articles is rightly subject to a tighter and (in a sense) more tabloid style. Charles Matthews 19:03, 30 March 2007 (UTC)

I agree, but I think "In the mathematical field of..." does this. Do you agree? (This is one reason that I posted.) Geometry guy 19:25, 30 March 2007 (UTC)

When I first saw the article titled schismatic temperament, I was the uninformed reader. I knew the usual meaning of the word schismatic and the usual meaning of the word temperament, so it sounded like an article about a psychiatric disorder. It's actually about musical tuning. That's why quick orientation of the uninformed reader is needed. In some math articles, the non-mathematician reader could go through the first paragraph before finding out it's not about about chemistry, theology, archeology, etc.

I think that saying "In the mathematical field of ..." suffices. "In algebra..." or "In geometry..." probably also suffices. "In analysis..." often would not suffice given the plethora of different meanings of that word. Michael Hardy 19:42, 30 March 2007 (UTC)

I usually prefer something more explicit than "in mathematics". I expect analysis is more likely to cause confusion than, say, matrix theory. A helpful test is whether the broad topic requires disambiguation. If it does, then I have no problem with Geometry guy's concise phrasing. --KSmrq^T 04:00, 31 March 2007 (UTC)

Here is an example similar to user:Geometry guy's from a page I've edited recently:

Hilbert space is a mathematical construct (...)

In this case starting

In mathematics, Hilbert space is (...)

creates more problems than it solves: does it not imply that in physics Hilbert space means something else? I find it annoying, by the way, when the lead to an article with an elegant or not so elegant, but, at any rate, well thought-out solution is edited down to "In mathematics" with a happy note "boilerplate" in the edit summary. Arcfrk 08:26, 31 March 2007 (UTC)

I couldn't resist; I tried my hand at revising the intro to Hilbert space with completely different wording. (No doubt my hand will be bitten off.) I worry that the opening sentence is a long and winding road, but I hope it's one that the average reader can follow. Of course, it's impossible to make anything "idiot-proof"; idiots are so clever at finding new ways to misunderstand. ;-) --KSmrq^T 21:19, 31 March 2007 (UTC)

Certainly, writing

Hilbert space is a mathematical construct...

sufficiently notifies the lay reader that mathematics is what the article is about. Michael Hardy 23:30, 31 March 2007 (UTC)

I would just comment here that I don't think it's very helpful to link the word "mathematical" to the mathematics article. There are three good reasons to link a phrase: Because a reader might not be sure what it means, because it provides information helpful to understanding the article it's linked from, or because readers of the linking article are especially likely to want to see it.

The first reason will never apply; the second very rarely, the mathematics article being much too general to be helpful in the specialized articles we're discussing. The third reason also strikes me as a bit unlikely -- if a reader has wandered in by mistake he really just needs to know that this isn't what he's looking for, and if he's there on purpose he's probably more interested in the article on the specific field of mathematics.

Summing up, I prefer "in the mathematical field of foo theory...", with no link on the word "mathematical". --Trovatore 18:48, 3 April 2007 (UTC)

This is a really helpful comment. I'm tempted to go right away to the articles I have edited and remove the link. Do others agree? Geometry guy 19:01, 3 April 2007 (UTC)

I really like Trovatore's suggestion. Seems very reasonable. VectorPosse 23:36, 3 April 2007 (UTC)

I agree with not linking "mathematics". However, I'd like to question whether it's necessary to mention the field within mathematics. Of course, it depends on the circumstances, but I think it's done too much. For instance, here are the first sentences of two articles that came up on my watchlist:

• "In mathematics, especially in elementary arithmetic, division is an arithmetic operation which is the inverse of multiplication."
• "In mathematics (specifically linear algebra), the Woodbury matrix identity says that the inverse of a rank-k correction of some matrix can be computed by doing a rank-k correction to the inverse of the original matrix."

I'd argue that in both cases it's of little use. In the first case, I wouldn't even mention mathematics, and just start "Division is an arithmetic operation which is the inverse of multiplication": if the reader doesn't know what division is, does it help to mention mathematics? In the second case, the word matrix tells the reader that it's a topic in matrix theory / linear algebra, unless of course the reader doesn't know what a matrix is, in which case linear algebra probably won't mean much either. -- Jitse Niesen (talk) 02:19, 4 April 2007 (UTC)

Don't look now, mathematics is going to be an orphan at this rate. I think that Build the web is a little relevant here. I kinda disagree with Jitse, in that if someone happens on an article like term algebra, the immediate link to universal algebra is useful. Smmurphy^(Talk) 02:50, 4 April 2007 (UTC)

If WP:BTW is relevant, so is WP:CONTEXT. Here's how I see it: Think of a tree going from general at the root to specific at the leaves. It's very natural for more general articles to have links to more specific ones, but links the other direction are usually somewhat less useful. Extremely general articles, like mathematics, don't need many links to them, because they're likely to be primary search terms.

In general I think a link one step "up" the tree (my trees have the root at the top and the leaves at the bottom, don't ask me why) is useful, but going all the way up to the root is not. So pointclass should say it's in the context of descriptive set theory, which in turn should say that it's part of mathematical logic, and that last article might link to mathematics. In the other direction, from the root to the leaves, leap by as many stepas as you feel like.

As to Jitse's point, I pretty much agree on division (though a link somewhere to arithmetic wouldn't hurt; that's just one step "up"). On Woodbury matrix identity I'd probably throw in linear algebra, unless there's a narrower subfield that would be useful to mention instead. --Trovatore 03:04, 4 April 2007 (UTC)

I think I agree with Trovatore here. When the lead sentence links to mathematics, it makes the reader recreate the context all the way back to the current article. If the lead links to a subfield, it makes the user back up only one level. Presumably that article allows the user to back up another level, and so on until the reader finds a comfortable article. So in most cases I think it is better to link to the general subfield of mathematics, when possible. But as long as there is a link in the opening paragraph it doesn't matter so much whether it's in the first sentence or not. CMummert · talk 03:18, 4 April 2007 (UTC)

I'm already on record as preferring to name a context more specific than mathematics. Now I shall attempt to illustrate why it's a good idea to provide context even when the context seems obvious. I'll use the examples given, "division" and "Woodbury matrix identity". The American Heritage Dictionary definition of division includes

• 1.f. A group of several ships of similar type forming a tactical unit under a single command in the U.S. Navy.
• 1.g. A unit of the U.S. Air Force larger than a wing and smaller than an air force.
• 1.h. Variance of opinion; disagreement.
• 2. Mathematics The operation of determining how many times one quantity is contained in another; the inverse of multiplication.

My point is that what seems "obvious" when we're thinking about mathematics may not be what the reader had in mind; our definition is secondary to these others! Likewise, our meaning for "matrix" comes eighth; a geologist naturally assumes we're talking about "The solid matter in which a fossil or crystal is embedded." Unless we tell otherwise. Which is what we should do. --KSmrq^T 08:03, 4 April 2007 (UTC)

That sounds right to me. Smmurphy^(Talk) 12:51, 4 April 2007 (UTC)

I believe I was not very clear. I agree that there should be a link to some specific context. My point was that we should be more creative than the standard template, because the first sentence of an article is often rather convoluted. It is easy to end up with beasts like "In mathematics (more specifically topology), the Poincaré conjecture (pronounced pweh-cah-ray, IPA [pwɛ̃kaˈʁe]), which is named after Henri Poincaré who formulated it in 19xx, states that …"

Here is what I'd prefer in the examples I gave:

• "Division is an arithmetical operation which is the inverse of multiplication."
  The idea is that arithmetical signals which meaning of division we're talking about (though I'm willing to concede that this might be a bit too subtle and that we should start with "In mathematics, division …").
• "In mathematics, the Woodbury matrix identity says that the inverse of a rank-k correction of some matrix can be computed by doing a rank-k correction to the inverse of the original matrix."
  Here, matrix (mathematics) gives better context than linear algebra, and mathematics is mentioned at the start so it's clear we don't mean the geologist's matrix.

I think these formulations make the context sufficiently clear. -- Jitse Niesen (talk) 15:11, 4 April 2007 (UTC)

If the article title is a dab title like Division (foology), where foology is a field with its own terminology, then – assuming the article title is aptly chosen – it is entirely appropriate to start with a sentence such as "In foology, the separation of an entirety into several parts is called a division."  --Lambiam^Talk 15:46, 4 April 2007 (UTC)

Wikipedia poll on Attribution now open

Further to the discussion above (Wikipedia talk:WikiProject Mathematics#Attribution), the poll on the new WP:ATT summary of the verifiability and no original research guidelines is now open, and closes on April 6th. So far it looks close, so please vote to give the mathematicians' point of view.

It is my strong belief (and I am not alone, see above), that the proposed change is definitely a good thing for mathematics, since it reemphasises "attributable" (i.e., the fact that an article has sources) rather than "attribution" (choosing a particular source and citing it). Also, "no original research" would follow as consequence of being attributable, rather than a directive in itself. In some sense, every wikipedia article is "original research", because it gathers information from a variety of sources and presents it in a new (and hopefully fresh, lively and interesting) way. This is particularly true in mathematics, where an encyclopedic explanation of a fact requires careful writing in a novel way, even though there are hundreds of sources. This change, although clarifying existing policy, should help us (I'm an optimist) against the bureaucrats who insist on an inline citation to source every nontrivial sentence.

I also happen to think the change is good for wikipedia, because in other fields, the concept of "truth" is less clear-cut than it is in mathematics, and by replacing "verifiable" by "attributable", the role of an encyclopedia to describe knowledge (which is partly what people believe rather than what is true) is greatly clarified. Geometry guy 19:27, 31 March 2007 (UTC)

The poll is actually here: Wikipedia:Attribution/Poll. I voted against, because I didn't see how the new thing fixed the problem of bureaucratic insistence on citations, while at the same time, it seemed loosen structure enough to allow propaganda and misinformation to be included in a back-handed manner, simple because its "attributable". Its precisely because "truth" is less clear-cut in other areas that it needs to be more carefully defended. linas 05:15, 3 April 2007 (UTC)

I was probably being a bit polite when I said "less clear-cut", as people can disagree quite vehemently on what the truth is, or even what "truth" means, which is why I find it not a terribly helpful term. I'm not actually sure what it means in general, and the wikipedia article on truth, while an interesting and amusing read, left me none-the-wiser! :) More seriously, I share your concerns, but hope that WP:ATT, backed up by a clear idea of what a reliable source is, will actually tighten the structure through its clarity. Geometry guy 13:14, 3 April 2007 (UTC)

Moving pictures and the Tesseract on our Project page

I really do not like moving illustrations in articles (unless they only move when you click on them or some such). They are distracting and the use up the band-width of my modem connection. In some cases, the article never settles down enough for me to see what is there and edit it. In this particular case, I would like to ask whomever is responsible for the moving picture of a tesseract on our project page to please fix it so that it does not move or only moves when the reader clicks on it. Thank you. JRSpriggs 07:04, 1 April 2007 (UTC)

It was added in this edit. If you don't like it, you can replace it yourself by another image you prefer. I don't think the wikimedia software currently offers the ability to start and stop animations; this is just a gif and the animation is that of your browser's renderer. In this case the file size is 491 KB, which is not excessive, and once loaded, it should not use up further bandwidth. Perhaps blanking an imagine could be realized with a JavaScript function in a user's monobook.js.  --Lambiam^Talk 09:49, 1 April 2007 (UTC)

I replaced it with a still image, but I view the current image as a temporary choice. It would be nice to get a sense of what people think about having an image on the project page. If there will be an image, suggestions of images would be welcome. I am inclined to agree that moving images are distracting. CMummert · talk 12:42, 1 April 2007 (UTC)

There's always the solution realized on the tesseract page itself (see the "net"): a still picture with a link in the caption to "view animation". This partly addresses JRSpriggs's request, though of course it would be nice not to have to leave the page to see the animation. Ryan Reich 13:59, 1 April 2007 (UTC)

I looked for a still version of the previous image but didn't see one. I think it's a good idea. If you can make a still image, feel free to do so and then edit the project page accordingly. CMummert · talk 00:49, 2 April 2007 (UTC)

To CMummert: Thanks for replacing it.

To Lambiam: I see it in your diff, but I do not see it in the source of the page itself. Is it in an included file? JRSpriggs 10:27, 2 April 2007 (UTC)

The source of which page are you referring to, and what is the it you don't see there?  --Lambiam^Talk 17:31, 2 April 2007 (UTC)

The image is included from Wikipedia:WikiProject Mathematics/Nav, which is available from the "edit" link in the resources column of the main project page. This isn't obvious from the way that the page is structured, but there aren't a lot of good places to put the edit link for the sidebar. CMummert · talk 17:49, 2 April 2007 (UTC)

I've replaced the image by a still version of a newer animated image with "glass" faces, and provided a link to the animation as suggested above by Ryan Reich.  --Lambiam^Talk 18:01, 2 April 2007 (UTC)

My thanks again to CMummert, Ryan Reich, and Lambiam. It is much better now. JRSpriggs 08:06, 3 April 2007 (UTC)

Rao integral equation

I wonder what people think of the recent additions to integral equation. To me at appears that it is not yet well-enough established research (see the references section) to show up on Wikipedia. Comments? Oleg Alexandrov (talk) 04:25, 2 April 2007 (UTC)

"Not well-enough established" is too polite. Kill it. Jmath666 07:50, 2 April 2007 (UTC)

I tend to agree. Policy wise it seems to fail WP:OR, WP:RS. This stuff may be true, but it could be duplication of other work under a new name. However I think I can vouch that Rao is actually a distinguished computer vision worker. I met him one at the Newton institute in Cambridge, so it not a straight forward crank case. --Salix alba (talk) 10:15, 2 April 2007 (UTC)

There is a photo here, if you remember the face. --KSmrq^T 17:22, 2 April 2007 (UTC)

This is Dr. Murali(dhara) (Subba)Rao from Stony Brook.[23][24] Is this the same Rao you met, or was that this Murali Rao? The mathematics seems genuine to me, but nevertheless it is reasonable to wait until we have a reference from a peer-reviewed source.  --Lambiam^Talk 13:05, 2 April 2007 (UTC)

I looked at the professional publications listed at his university page, and found not one about "Rao transforms". Charitably, perhaps he is trying to secure international patents before he publishes, and we know journals can have long delays between submission and publication. Uncharitably, most researchers consider it bad form to name something after themselves; such names are best bestowed by others. If he wishes to promote his ideas for financial gain, that is his choice; but if he wishes to use Wikipedia to help him do so, without peer-reviewed publications to back it up, we must decline. --KSmrq^T 17:22, 2 April 2007 (UTC)

OK, I removed the Rao transform from Integral equation (and also Fredholm integral equation, and Volterra integral equation which were edited later). I mentioned to Dr. Rao (more precisely, to the anon address who edited) about WP:NOR and asked him to comment here if he has objections. Oleg Alexandrov (talk) 15:04, 2 April 2007 (UTC)

(The comment below is from my talk page. Oleg Alexandrov (talk) 01:57, 3 April 2007 (UTC))

I am new to Wickipedia contribution and I was not aware of the policy that material should have been published in well recognized journals. My contribution was made in good faith with a view to benefit the readers and enhance the value of Wickipedia. Now I know the policy of Wickipedia, and in this case it is likely to be a limitation of Wickipedia. You can read an expert review of my work here: http://www.integralresearch.net/#Expert_Review . Please see page 4 here which establishes the link between standard integral equations and Rao Integral Equations: http://www.integralresearch.net/wps.pdf . It is easily verified. As for naming my result, if my result is very important, then it is appropriate, and I believe it to be so. I am confident that my results will become "well established" in time. I am not in any hurry. I have protected my idea by applying for US patents. In public interest, in order to evaluate the correctness of my idea, if any qualified person volunteers to verify my results on behalf of Wickipedia, I can send one copy of my book free. But you can get a lot of information on my approach here: http://www.integralresearch.net/RTslides.pdf http://www.integralresearch.net/wps.pdf http://www.integralresearch.net/apex.pdf

Lastly, if someone shows that my new method of solution to solve the Fredholm Equation of the First Kind when applied to shift-variant image deblurring is not better than current methods, I will give them $250.

If you volunteers are serious about enhancing Wickipedia, you should restrict your comments to technical merits of my idea and point out technical weaknesses. Keeping the interests of Wickipedia and the users in mind, you can decide whether your want to post my method or not, is upto you.

I appreciate the voluntary service your are rendering to the public. Dr. Muralidhara SubbaRao (Rao) rao@integralresearch.net —The preceding unsigned comment was added by 24.47.184.148 (talk) 23:33, 2 April 2007 (UTC).

Greetings, Professor, and welcome to Wikipedia. We very much appreciate your wish to contribute. Our decision not to accept this particular item is not meant as a reflection on the merits, pro or con. We must ask you to accept the limitations of Wikipedia. Let me briefly explain. We have many thousands of articles on mathematics alone, and we simply do not have a sufficient pool of qualified editors, nor a procedural equivalent of peer review, to weigh the merits of novel unpublished material. No doubt this sometimes means we must forgo the inclusion of valuable new ideas from the cutting edge of research. But the fact is, we are hard pressed to supervise the accuracy and readability of material on topics already published in reputable journals. So we have decided, as a matter of policy, to not accept unpublished material. Perhaps in the future this will change; but for now, we have the awkward task of explaining our limits to enthusiastic new editors such as yourself who are unaware of our restrictions. Please feel free to contribute in other ways, within our limits. We could use the help! --KSmrq^T 03:43, 3 April 2007 (UTC)

requesting help at randomness

A new user calling himself MrMiami has been adding some bizarre nonsense to randomness that claims that, if a probability can be assigned to something, then that thing is "ordered" and therefore "not random". I don't think he's likely to see reason. Please come help. --Trovatore 18:03, 2 April 2007 (UTC)

It's not bizarre nonsense - it's theology. (Err... perhaps I should think that through again ;->) But the sources he cites are clear, for instance C. S. Lewis. He may have misunderstood them; but it is more likely that they are appealling to a pre-Laplacian vague concept of "randomness". Septentrionalis PMAnderson 03:21, 4 April 2007 (UTC)

Did Lewis claim that randomness cannot be mathematically modeled? I'm not aware that Lewis ever wrote on mathematics. Anyway the material I was referring to was (mostly) in the section called "In the physical sciences"; Lewis can hardly be taken as a source there. --Trovatore 03:24, 4 April 2007 (UTC)

There he seems to be trying to say that no single sequence is random, which is more or less true ("randomness" is a property of an ensemble of sequences). Saying so might help. Septentrionalis PMAnderson 03:35, 4 April 2007 (UTC)

Look back in the history a little further; you'll see what I'm talking about. OK, I'll dig up the diff for you: this diff. --Trovatore 03:37, 4 April 2007 (UTC)

Yes, that's what I meant. This is trying to say, strained thtough a lay understanding, that "a random sequence" is uncomputable. It is true that "almost all random sequences" are incomputable; there are only a countable number of algorithms. Septentrionalis PMAnderson 03:42, 4 April 2007 (UTC)

No, that's not what he means. Look at the talk page. He says quite clearly that if an event has a probability, then it's not random. --Trovatore 03:46, 4 April 2007 (UTC)

Rose (mathematics)

Can someone please check over the area section I added here to make sure it's alright? Thanks :-) —METS501 (talk) 20:39, 2 April 2007 (UTC)

The areas are correct. Those b's in the second equation should be k's yes? I don't know what you mean by "therefore integrals of the form..": do you mean that this applies also to rose curves defined with sine? That would make sense. Also, since the integrands are the same, the antiderivatives are identical, so the intermediate step shown between the integral and the area should (or at least could) look much more similar. Cheers, Doctormatt 21:26, 2 April 2007 (UTC)

After a couple of stabs at it, I think I've fixed the ambiguity. VectorPosse 22:12, 2 April 2007 (UTC)

The areas are not given by the same integral. For odd parameter, the limits need to be 0 to pi, and for even paramater, 0 to 2pi. The earlier version was correct. Cheers, Doctormatt 22:15, 2 April 2007 (UTC)

Yup, I got confused for a moment. It's correct now, I think. VectorPosse 22:27, 2 April 2007 (UTC)

Looks good. Nice improvement. Cheers, Doctormatt 23:22, 2 April 2007 (UTC)

Thanks everyone! :-) —METS501 (talk) 02:47, 3 April 2007 (UTC)

Math portal

Portal:Mathematics looks kind of odd these days, with redlinks for the article of the week and picture of the week. From the history it appears that this state of affairs was present for a while. Anybody knows why things are like this? Oleg Alexandrov (talk) 02:08, 3 April 2007 (UTC)

Fropuff fixed it (that was quick :) Oleg Alexandrov (talk) 03:31, 3 April 2007 (UTC)

These things will happen from time to time if the portal maintainers (presently myself and User:Tompw) are remiss in their duties. Somewhere I'll put up a set of instructions on how to fix things should this happen again (which I'm sure it will). In the meantime, feel free to pester Tompw or myself if something is wrong with the portal. -- Fropuff 23:54, 3 April 2007 (UTC)

Equilateral triangle

Equilateral triangle redirects to triangle. Shouldn't there be an own article for it? -- 212.149.217.110 18:59, 3 April 2007 (UTC)

Well, if there is enough material concerning equilateral triangles, it should be separated. But, what (besides the definition and perhaps how to construct them) would be in this separate article? Jakob.scholbach 20:32, 3 April 2007 (UTC)

There are plenty of topics that already link to equilateral triangle. Perhaps some of them would be relevant for an article on equilateral triangles themselves? —David Eppstein 21:16, 3 April 2007 (UTC)

I think there is plenty which is specific to the Equilateral triangle so I've reverted back to before it was a redirect and added a few things. --Salix alba (talk) 08:19, 4 April 2007 (UTC)

Lie groups

I've noticed that User:Smylei, with the only contributions in the areas of Television and Uncyclopedia under his belt, has removed a paragraph from the history of Lie groups, and I reverted it as vandalism. However, since he insists that he is right, and I am an interested party, having written the section, I would like to ask other mathematics editors to take a look. Arcfrk 23:07, 3 April 2007 (UTC)

Septentrionalis put it back in and I agree that it's fine. Arcfrk, keep in mind that vandalism is quite an accusation (it means that somebody is deliberately trying to compromise the integrity, per Wikipedia:Vandalism). While I struggle to understand Smylei's comments, I try to reserve the vandalism accusations for the most clear-cut cases. -- Jitse Niesen (talk) 01:15, 4 April 2007 (UTC)

Thanks for the reference. Indeed, according to the policy page you've mentioned, removing parts of the text, even if it looks random or is accompanied with disparaging comments, does not constitute vandalism. So what is it called, then (e.g. for the purpose of motivating a revert)? By the way, I reverted and put a note here before I saw his comments on the talk page. Arcfrk 01:37, 4 April 2007 (UTC)

I think what you may be looking for is "Don't be dense", which refers to Hanlon's razor.

There is another consideration, as well. You're new to this wiki, so may not have seen the {{test}} message left on someone's user page when they have done something untoward to an article. If you visit the template page, you will see that we have a very mild version at first, becoming progressively more firm. One reason is because vandalism is often a "Hey, look at me!" message, intended to provoke a strong reaction; we don't want to give them that reward. Another is because kids experiment. Yet another is because people make mistakes. If we call someone a vandal, they may choose to identify themselves that way and act that way, whereas if we take this approach, perhaps they will become good contributors. (And if not, we gave them every chance.)

We still have to deal with bad judgment, bad knowledge, and strong differences of opinion. Most of our editors make consistently helpful or harmless contributions; a very few are distressingly consistent the other way. We do the best we can with an encyclopedia that "anyone can edit". --KSmrq^T 03:56, 4 April 2007 (UTC)

Computational mathematics

I wrote computational mathematics (last version edited by me), which User:JJL proposes to replace by redirect to computational science with some additions there. Please see Talk:Computational mathematics and Talk:Applied mathematics#Computational mathematics for details. Jmath666 04:16, 4 April 2007 (UTC)

I can tell how I use the terms:

• numerical analysis = the development, analysis and application of algorithms for problems in continuous mathematics.
• scientific computing = same, but with more stress on the applications and less on the analysis
• computational science = even more stress on applications
• computational mathematics = as numerical analysis, but not restricted to continuous mathematics. Includes for instance computational number theory, complexity theory and symbolic computation.

For me, the first three terms are almost synonymous and they can perhaps best been described in one article. Computational mathematics is quite different, but also a collection of disciplines with little overarching concepts so it will be hard to write an article about it. Furthermore, all these concepts are rather amorphous and discussions about their proper definition tend to not very fruitful so I usually stay away from them. -- Jitse Niesen (talk) 05:45, 4 April 2007 (UTC)

JJL, I see you have reverted my edits to scientific computing that made a distinction between computer science and computational mathematics, consistently with your POV about computational mathematics. I suggest to wait for the outcome of the discussion here. Jmath666 05:54, 4 April 2007 (UTC)

I apologize if this historic view may be incorrect in details. Computer science a.k.a. Informatics split off from mathematics and electrical engineering sometime in the 1950s and separate CS departments started to appear in the 1960s. The term computational mathematics (CM) was used for numerical analysis as well as other computing things done on the math side, see the 1985 Rheinboldt report Future Directions in Computational Mathematics, Algorithms, and Scientific Software commissioned by NSF. A DOD commisioned position paper (page 45) refers to CM as "The Mathematics of Scientific Computation". This report was followed by the NSF program in CM which currently defines its scope by: "Supports mathematical research in areas of science where computing plays a central and essential role, emphasizing algorithms, numerical methods, and symbolic methods. The prominence of computation in the research is a hallmark of the program." Meanwhile, the 1982 Lax report Large Scale Computing in Science and Engineering commissioned by NSF and DOE was the beginning of substantial funding for (and thus the very existence of) what was at different times called Large scale computing, High performance computing, Supercomputing, and Computational science. (The reason for evolution of names was mostly political, to justify funding for something new, buzzwords get tired.) [Added: Scientific computing seems to be a more general term for everything here, used already before 1980.] To date, computational mathematics kept its identity as the theoretical side of things (mostly of us do proofs) distinct from Computer science (only the complexity people still do proofs) [Added: and Computational science (what proofs?)]. So that is my take, which includes sources. Maybe too much original research for an article unless I am lucky enough to find an independent history source. Jmath666 06:32, 4 April 2007 (UTC)

Added: SIAM Timeline says the Rheiboldt report "led to the High Performance Computing initiative.". Jmath666 15:44, 4 April 2007 (UTC)

With terms that overlap in meaning, and that are used in different ways by different people, it is always difficult to draw boundaries. Unlike Jitse, for example, I perceive a clear distinction in focus between numerical analysis and scientific computing/computational science. To me, numerical analysis is a field within mathematics, practiced by mathematicians. It is traditionally more about methods or algorithms than about programs. The abstractions addressed by these algorithms are still clearly within the realm of mathematics; they offer methods for solving, for example, a certain type of pde. Scientific computing, on the other hand, is typically an activity that takes place in the context of a class of problems specific to some science, like protein-protein interaction prediction, even when it draws heavily on methods of numerical analysis. But then, of course, the numerical challenges of the Navier-Stokes equations are such that for example in computational fluid dynamics you can't tell where the researcher stops being a numerical mathematician and becomes a computational scientist. Now I think of computational mathematics as a generalization of numerical analysis: computing in the context of a mathematical class of problems, and as such being within mathematics and practiced by mathematicians. To the extent that we do not consider mathematics a science, it would not classify as one of the computational sciences, just like computational linguistics does not. A final remark: in general it does not make for pleasant reading if the introduction to a topic starts with an enumeration of everything it should be distinguished from or not be confused with, something that is hardly helpful to the typical reader who has only a vague idea of what all these things are. Better to focus on what it is and push such distinctions to a section at the end like Related fields.  --Lambiam^Talk 07:45, 4 April 2007 (UTC)

There is certainly scope for historical writing on half a century of computation. It should probably be clearly flagged as history, though. OR is really a concern when there is some spin being put on the material; I wouldn't worry about it for a timeline article. Charles Matthews 10:13, 4 April 2007 (UTC)

I feel we're really splitting hairs between num. anal., num. methods, computer/computational sci./eng., computational math., sci. computing/computation., etc. There's a clear line between computer science on the one end and computer eng. on the other, but the rest are muddled. If we have an article for each then I think OR/POV is inescapable. We'll all have different views on this; I think redirecting to a computational science article is most sensible. What meaningful content goes in computational math. but not in computational science and/or sci. computing? I would agree that computational math. is more aligned with numerical analysis--I don't draw the distinction, personally--and feel that sci. comp. is the next step toward computer science, and that computational science is a more interdisciplinary field. Looking at the two SIAM journals in this area and their CS&E conference (which I just attended in the OC), I feel the distinctions are very minor and far from agreed-upon. It's more a matter of how one prefers to be identified, for the most part. I've known some great numerical analysts who knew very little about actually using a computer themselves, but that was back in the 80s--no one is in that boat nowadays (thank you, MATLAB). I think num. anal. deserves a page and computational sci. does, but comp. math. is just multiplying entities beyond necessity. That some groups use a different term doesn't move me. JJL 13:20, 4 April 2007 (UTC)

Thank you. There are still great numerical analysts and even engineers who do not program, not even MATLAB, and will be. I am familiar with the the SIAM CS&E conference though I sent there someone with the paper instead of going myself. Yes, the distinctions are blurred. Some are along the line proofs/no proofs. Some are what is done in what department / academic program / center.

Perhaps someone could take an integrative view on the whole business of applied mathematics / computational mathematics / computer science / computational engineering / computational simulation / large scale simulation / large scale computing / supercomputing / high performance computing / scientific computing / scientific computation / numerical analysis / numerical mathematics [Added: / computational science] etc. and make some sense out of it. Maybe start with disambiguation page and/or a category. What we have is an inconsistent hodgepodge of separate articles, written at very different levels of expertise. The separate pages or sections should give attribution for whatever they say instead of POV. I'd think the role of major conferences, commissioned panels, editorial policies of journals, funding agencies programs, and funding initiatives in naming things and distinguishing fields is notable and also provides the required citations not otherwise available and will help to avoid editor's POV.

Right now, the question is: should computational mathematics be remain a separate page or not? Jmath666 16:23, 4 April 2007 (UTC)

Tagging math articles

It appears that User:Parker007 has asked User:Snowbot to tag a lot of math article talk pages with {{maths rating}}. Has anyone heard anything about this? CMummert · talk 00:50, 30 March 2007 (UTC)

Nothing beyond the obvious activity on my watchlist. But I don't see any particular harm in tagging them all. —David Eppstein 03:10, 30 March 2007 (UTC)

The consensus the last time it was discussed was not to do it. The bot doesn't actually rate the articles, it just puts the tag on them, so a real person still has to do the work. In which case there is no real reason to add the tag. Also, thousands of articles will only slow down User:WP 1.0 bot more than it is currently slow. About half articles in the master table are in the "no grade/no importance" entry of the table. CMummert · talk 12:49, 30 March 2007 (UTC)

Snowbot has now been stopped. Thanks to all of you for addressing the issue. The bot has tagged about 1.6K talk pages, what I need to know if the project want them to be detagged or not. Snowolf ^(talk) _CON ^COI - 13:31, 30 March 2007 (UTC)

Unfortunately it stopped at the letter 'S'. There was also a bug which meant it tagged articles which already had a "math rating" (spelt without an s). If we want for all these pages to be detagged, we need to be sure Snowbot will only detag the pages it tagged, and not previously tagged pages (which may reflect editor priorities). Otherwise, I suggest we let it finish the job: there are only a few letters remaining. Geometry guy 14:04, 30 March 2007 (UTC)

I'm looking at Wikipedia:WikiProject Mathematics/Table. I would support removing the math rating tag from all the articles that are both "Stub-Class" and "Unassessed importance". It is OK when someone manually adds a tag with these settings, because then someone else can go through and assess the importance and field, but there are currently 2300 such articles, more than we can expect anyone to go through by hand. We might as well clear them out and then pick up with the manual rating again. This is just my opinion. The user who requested the tagging has not yet commented on his/her goals for doing it. CMummert · talk 14:10, 30 March 2007 (UTC)

Would anyone object to the removal of certain tags as described in my previous comment? CMummert · talk 03:10, 4 April 2007 (UTC)

I support this, especially if Snowolf can persuade Snowbot to remove only the tags of this form which were previously placed by Snowbot: if the bot can read the recent edit history it should be possible. Geometry guy 19:58, 4 April 2007 (UTC)

I support removing auto-tagged articles - it serves no use. (Btw, if the bot can't read the edit history, it could just remove stub-class unassessed-importance articles in Category:Unassessed-field mathematics articles). Tompw (talk) 20:13, 4 April 2007 (UTC)

In my opinion, it would be fine to make a list of the intersection of those categories and ask SnowBot to untag those articles. I have been manually assigning importance ratings to articles periodically, so not very many of the articles with "unassessed" importance were manually added. CMummert · talk 20:25, 4 April 2007 (UTC)

It should be unassessed importance plus unassessed field. I went through and assigned a field to some of those articles, but not always an importance; those tags could maybe be left in place. --Trovatore 20:50, 4 April 2007 (UTC)

I would generate the list fresh, so articles that have been rated by hand ought to be left alone. There are currently 2153 articles in both Category:Unassessed-importance mathematics articles and Category:Unassessed-field mathematics articles. That seems like a reasonable set from which to remove the tags. I would make sure that every article with a quality class other than stub has an importance rating before making the list, so those would not be untagged. CMummert · talk 21:35, 4 April 2007 (UTC)

User:SnowBot is making the changes now; I estimate it will take about 8 hours from now to go through the entire list. CMummert · talk 15:48, 5 April 2007 (UTC)

Request tags be put back. It's useful information for users that the articles fall within the scope of Project Mathematics, and this should be indicated on their page.

It is a good thing for articles to be tagged with a Project, so people know where to come to for experts. And so 'bots can easily ID the subject matter, just from a links dump. Jheald 18:13, 5 April 2007 (UTC)

There is already a system for identifying which area the articles are in: categories. They allow User:Mathbot to generate the list of mathematics articles. The project banner is for rating the quality of articles in the WP 1.0 scheme. It does no good to put on the banner if every article ends up "unrated". This was discussed last fall and the (unanimous) consensus then was not to put the banner on every math article. User:Parker007 asked for the articles to be tagged without bringing it up here; the untagging is essentially just restoring things to the way they were before then. CMummert · talk 18:34, 5 April 2007 (UTC)

There is a great opportunity here for editors to go through Snowbot's recent edit history and tag any articles they think deserve a tag (with rating, importance and field of course). I did a small handful recently. It doesn't take long to scan through the list, particularly if you just want to tag a small number of articles. Geometry guy 12:04, 6 April 2007 (UTC)

Use of quantifiers ('for all', 'there exists')

I don't seem to find any previous discussions concerning the use of quantifiers (e.g. $\forall ,\exists$, as in the definition section of Inner product space) in articles (I might be bad at searching, though). I personally think these should not be used in a 'textbook' setting, and they greatly reduce readabillity. Granted, they provide a clean and very clear exposition for readers who are comfortable with them, but since articles are usually directed to a general audience, I think they should be avoided. Comments? JohanK 07:51, 4 April 2007 (UTC)

They should be avoided, except in logic articles where they have a legitimate reason to be used. We 'expand abbreviations' routinely, and if quantifiers are just used to avoid writing words in plain English, they should be expanded.Charles Matthews 10:10, 4 April 2007 (UTC)

Our Manual of Style says:

In particular, the English words "for all", "exists", and "in" should be preferred to the ∀, ∃, and ∈ symbols.

I think there hasn't been any discussion about it because everybody agrees that quantifiers should be avoided (though I have far less problems with using ∈ instead of "is an element of"). -- Jitse Niesen (talk) 11:02, 4 April 2007 (UTC)

Let $Q={\mbox{quantifier}},$ $W={\mbox{Wikipedia}}$, and $M={\mbox{math style manual}}$. Then,

$\forall Q\in W:M\Rightarrow {\mbox{expand to plain English}}(Q).$

Oleg Alexandrov (talk) 15:00, 4 April 2007 (UTC)

What about a page like peano's axioms. As its dealing particular with set theoretic concepts it seems somewhat appropriate to use this notation. Expanded it could become quite unwieldy. --Salix alba (talk) 18:39, 4 April 2007 (UTC)

Peano's axioms uses quantifiers only in quoting a set of equivalent axioms (from Kaye) which introduce addition and multiplication explicitly (and are therefore much longer). I wouldn't take the quantifiers out; but then I wouldn't have included Kaye's axioms either. Do you think quantifiers are needed anywhere else? Septentrionalis PMAnderson 19:16, 4 April 2007 (UTC)

Probably a case of ignore all rules there will always be exceptional cases, where the style can be broken. --Salix alba (talk) 19:28, 4 April 2007 (UTC)

The symbolic quantifiers in Peano's axioms are only used for a particular set of formal axioms; the rest of the article, which is not about the formalization, uses natural language. Other examples of this practice include Zermelo–Fraenkel set theory and Prenex normal form. It is only when we are discussing axioms qua symbolic expressions in a formal language that they should be written symbolically. In other contexts, when the actual formalization is not being discussed, symbolic quantifiers are avoided in published mathematical writing,and they should be avoided here too. CMummert · talk 19:46, 4 April 2007 (UTC)

There is a reason that formal languages were invented. Natural languages are very confusing and clumsy at expressing complicated concepts, e.g. when there are quantifiers in both the hypothesis and conclusion of an implication. See Transfinite induction for an example of a concept which is expressed very unclearly in ordinary English, but would be trivial in formal logic notation. JRSpriggs 10:21, 5 April 2007 (UTC)

Which is why our mathematical style guidelines advise moderation, not abstinence:

• Careful thought should be given to each formula included, and words should be used instead if possible. In particular, the English words "for all", "exists", and "in" should be preferred to the ∀, ∃, and ∈ symbols.

(Emphasis added.) The intent, as always, is clear, correct, and compelling communication with the reader. It would be lovely if we could just say, "Write well." :-) --KSmrq^T 11:28, 5 April 2007 (UTC)

Category:Applied Mathematics

Should there be such category? There was only Image analysis in it and the category page was blank. So have have changed Image analysis to Category:Mathematics. Jmath666 20:48, 5 April 2007 (UTC)

That's a upper-case problem; see Category:Applied mathematics. Charles Matthews 21:05, 5 April 2007 (UTC)

I see. So I have corrected the page pointing there. Jmath666 21:22, 5 April 2007 (UTC)

I've deleted the now-empty category. —METS501 (talk) 04:59, 6 April 2007 (UTC)

Need help with computational mathematics

I need some help there. From User:JJL on Talk:Computational mathematics: "I don't believe this is a separate field but rather a different name for what is now usually called computational science. I suggest redirecting it there and editing that article to mention that, indeed, computational science as a named academic program often has an emphasis on the applications to science." This [sentence] makes no sense. Some of you made few helpful edits to computational mathematics but that does not seem to be enough to make User:JJL go away and stop claiming that computational mathematics does not exist and pushing to delete the article. Thanks. Jmath666 00:40, 6 April 2007 (UTC)

The real problem is that no-one is wrong or right here. Some groups use the term in a way that is almost indistinguishable from computational science, except for the pretension that, since they are mathematicians, they must be doing it right. Others prefer to use the term differently. I think the first may have more clout.  --Lambiam^Talk 01:00, 6 April 2007 (UTC)

Of course. But the issue is that the article should exist and explain that. The different uses of the term can be easily supported by sources and I am not asking for help with that. I need support for the existence of the article. Jmath666 01:34, 6 April 2007 (UTC)

Calling for a straw vote

Do you think that computational mathematics should be a separate article or, as JJL suggests, redirected to computational science and that article edited by JJL "to mention that, indeed, computational science as a named academic program often has an emphasis on the applications to science" (sic)? Please vote separate article or redirect. Thank you. Jmath666 04:08, 6 April 2007 (UTC)

With the lame discussion we have had (for which I'm more than a little bit responsible, but which is most likely due to there being no persuasive arguments either way) I don't see how this will lead anywhere. Either approach (separate article, or redirect + treatment in Sci. computing) seems fine to me. What I find much more of an issue is that the current article Computational mathematics is a painful read, and when you manage to read through you emerge at the other end with the feeling "huh? what happened?". Merging it with Scientific computing will not improve the readability of the latter article – which itself offers considerable opportunity for improvement on the scale for reading pleasure.  --Lambiam^Talk 07:25, 6 April 2007 (UTC)

In the spirit of the previous comment, I'd like to concentrate more on the content than on the nomenclature. Neither article seems to mention any work on scientific computing (computation ?) in algebra. Yet, pioneering work on computer algebra systems, such as PARI and MAGMA aside, at the moment, number-therertic applications such as primality testing and factorization are arguably among the most important in the whole field of scientific computation (think RSA, cybersecurity, etc). Is there an article that discusses it? Which article would be closest in spirit to Richard Crandall and Carl Pomerance, Prime numbers. A computational perspective (ISBN: 978-0-387-25282-7)? Arcfrk 07:46, 6 April 2007 (UTC)

If the information in computational mathematics (not form) is preserved after such move that's OK with me too but given the attitude of JJL that is highly unlikely, please do read the quoted sentence above that shows it clearly. The current painful state of computational mathematics (yes I fully agree) emerged after me trying to respond to objections of JJL but that was a mistake obviously nothing will satisfy JJL given his POV that computational mathematics does not exist and it just messed it up.

I would not mind taking look at the whole scientific computing area and I suggested just that above and even wrote a rought draft of a the top article but there was no response. and I cannot afford the kind of struggle like with JJL reverting my edits every step of the way - too much waste. Can you look? Sorry I do not know anything about computing in algebra etc.

I can give it one last shot and rewrite computational mathematics completely reporting on documented facts not any editor's wish what is should or should not be. But I would like to see some interest/support before I take on that task. Thanks. Jmath666 08:37, 6 April 2007 (UTC)

• Carve up between scientific computing and numerical analysis. Reduce current article to no more than a dismabiguation stub. Jheald 10:25, 6 April 2007 (UTC)

• Redirect (and by the way, see WP:OWN). JJL 12:40, 6 April 2007 (UTC)

• Looking at the various orginisations, confrences and journals with computational mathematics in the title it seems the most of these would fit numerical analysis/scientific computation. There are others which seem to have a distinctive mathematical flavour The Complexity of Computing the Hilbert Polynomial of Smooth Equidimensional Complex Projective Varieties[25] and tend to fall under the Automated theorem proving and Symbolic computation. Following Arcfrk, I think there is a need for a general article on using computers in mathematics, detailing its history and some of the key moments say the Four color theorem, E8 (mathematics) and calculation of primes, but its not this article. This article should be kept short as it mostly mirrors other articles. --Salix alba (talk) 13:54, 6 April 2007 (UTC)

Thank you very much for the feedback. I have replaced the page by disambiguation. Jmath666 00:31, 7 April 2007 (UTC)

Lifting (mathematics)

I hastily created a stub article titled lifting (mathematics), and at this moment I'm not even sure I've got the definition right. Could others here add more? Michael Hardy 21:04, 6 April 2007 (UTC)

... looks like haste doesn't always make waste: several people have edited this thing that I put there in a few seconds without yet proving I included something horribly dumb in it. We'll see.... Michael Hardy 01:23, 7 April 2007 (UTC)

Yes, perhaps we should start a category "Collaboration of the last 30 minutes" :-) Jakob.scholbach 01:54, 7 April 2007 (UTC)

The most important thing is to include the diagram illustrating it. I think, User:Fropuff was offering his help with things like that. Arcfrk 02:43, 7 April 2007 (UTC)

I've regularly seen the term "lifting" with a quite different meaning; expressed categorically it would be the action of a functor on a morphism in the category Set. Examples are the "lifting" of a function from A to B to one operating on sets in the usual covariant way: from Set(A) to Set(B). An other example is how the addition operation of a field carries over to vector addition in a vector space over the field. Is this notion of lifting sufficiently standard and entrenched that it should be mentioned?  --Lambiam^Talk 07:59, 7 April 2007 (UTC)

I have not yet heard the word "lifting" in this context; rather extension (of the field operations to the vector space) or that a functor Fun(A, B) category inherits the properties of B. Jakob.scholbach 19:24, 7 April 2007 (UTC)

There are many uses of the term lifting outside of category theory. In Sobolev spaces, the extension operator (to extend a function from the boundary of a domain in Rⁿ inside, say) such that its norm is bounded in certain Sobolev norms, is sometimes called lifting (it is the opposite of the trace operator, which is basically a restriction). There are many papers on lifting of some operator in some functional spaces. Perhaps lifting is a general term that refers to a commutative diagram in a certain context. Jmath666 01:09, 8 April 2007 (UTC)

There is a (slightly) different usage within category theory - or at least within homological algebra, which at least formally is not the same thing:-)

Another common usage in `practical' homological algebra is within diagram chasing, where you lift elements (ultimately often in order to construct homomorphisms). Element-wise, a lifting of an element is simply a preimage of it; possibly involving an arbitrary choice of one out of many. In favourable cases, you may emply element-wise liftings in order to lift homomorphisms. Of course, this is not `the proper way' to do it, since not all caregories have forgetfulness functors to the category Set (even if small abelian categories may be represented thus). I note that Saunders Mac Lane in Categories for the Working Mathematician does not have a reference to either 'lift' or `lifting'; he does refer to digram chase, but spende the time with explaining how to do it 'using "members" (in A) instead of elements (in Ab)' (from section VIII.4, 'Diagram lemmas'). He very clearly assumes that the reader already is used to the concrete 'chasing elements around diagrams' technique from homological algebra.

See the enlightening discussion in Five lemma#Proof. There, too, 'liftings of elements' are not mentioned; but the following instance from the first proof:

• Since p is surjective, there exists an element d in D with p(d) = t(c′)

may be referred to thus: 'Since p is surjective, t(c′) may be lifted to an element d in D.' JoergenB 05:46, 8 April 2007 (UTC)

I believe this has gotten enough publicity here. Further discussion should move to the article talk page, where it will be found by future editors who may want to know what motivated our choices. --KSmrq^T 06:03, 8 April 2007 (UTC)

PanelWhiz

Cross-posted from Wikipedia:Requests for comment/Maths, science, and technology:

• Talk:Stata#PanelWhiz - Should external and wiki links to PanelWhiz be included in the Stata article? Is PanelWhiz notable? - 16:14, 7 April 2007 (UTC)

Tearlach 12:56, 8 April 2007 (UTC)

AfD nomination

Wikipedia:Articles for deletion/Curve transformation. The author of the page describes it as original research. Charles Matthews 19:16, 8 April 2007 (UTC)

AFD nomination

Wikipedia:Articles for deletion/Internet shorthand notation seems to be misnamed for what I've always known as "ASCII math notation". Note, there may not be one standard method, but I believe the overall concept is notable for an article, at least in terms of the history of computing. Yea or nay, I think this nomination needs more knowledgeable input. --Dhartung | Talk 21:55, 8 April 2007 (UTC)

Differential equations

I've come across the article Examples of differential equations which has been tagged as having insufficient context (in my opinion, rightly so), and following the links, found an article ordinary differential equation. Now, the interesting thing about it is that there is also an article differential equation which is not linked from the ODE page. Was there a schism a while back, with one school of editors leaving and founding their own page? What do other editors think about the current distribution of the basic material between different articles? (I'll mention two more: partial differential equation and phase portrait, which is just a stub with a picture.) Arcfrk 03:51, 6 April 2007 (UTC)

I don't know about the distribution, but an ordinary differential equation is a specific case of a differential equation, so they (rightfully) should have two separate articles. —METS501 (talk) 04:58, 6 April 2007 (UTC)

I've visited these pages a few times for various reasons, and am also somewhat unhappy with the current arrangement. It is mainly partial differential equation that fills me with despair, although I have been trying to keep quiet about it because a complete cure may be hard to find! The main problem, in my view, is that the article implicitly assumes (without stating it) that a PDE is just one equation (i.e. real-valued, rather than an equation in Rⁿ or some other space). This means in particular that the most fundamental trichotomy of PDEs - into the underdetermined, the determined, and the overdetermined - is not properly discussed. Instead aspects of this trichotomy (such as the h-principle) are mentioned in passing, and these discussions are consequently completely unilluminating.

I like the idea that differential equation provides an elementary introduction to the subject, but partial differential equation should then be a really comprehensive survey of the scope of this immense and hugely important field, rather than just a list of a few one variable examples (I am being a bit harsh here, I admit).

As for the sociological concerns about previous editorial groups, my experience so far at wikipedia suggests that the best approach is to read the edit history and then be bold! The quality of the article is what matters, not how it got there. If a complete rewrite is needed, go for it! Geometry guy 16:31, 9 April 2007 (UTC)

I could't find h-principle even after your tip, which is just as well, because there are even more fundamental concerns about that article, namely, that it somehow conceals the fact that there are (many!) important nonlinear equations, and we do have some theory (integrable systems, Hamilton-Jacobi, etc). The distinction between linear and nonlinear appears only casually in the middle of one section, and not given any serious treatment. Systems are mentioned, but only linear systems of first order! On the other hand, the article is fairly long as is, meaning, in particular unfocused. It the same story as with ODE, only worse (since the material is more complex). Should we propose them as collaborations of the week? Arcfrk 03:07, 10 April 2007 (UTC)

Rose (mathematics)

Should a formula be included for defining 2-, 6-, 10-, etc-petalled roses such as

$r=\cos(k\theta )(-1)^{\left\lfloor \displaystyle {\frac {\theta -\pi }{\pi }}\right\rfloor }$

or something? —METS501 (talk) 05:11, 6 April 2007 (UTC)

See WP:NOR.  --Lambiam^Talk 06:40, 6 April 2007 (UTC)

This is not original research. It may not need to be included, but original research is defined as "a term used in Wikipedia to refer to unpublished facts, arguments, concepts, statements, or theories, or any unpublished analysis or synthesis of published material, which appears to advance a position". This is clearly not to advance a position. I'm not getting rich off this :-) —METS501 (talk) 06:47, 6 April 2007 (UTC)

Also, I didn't say that this formula should be included. What I meant was should we put a note on the article that a (4k+2)-petalled rose can be created in other ways such as using the floor function or plus/minus sign on a (2k+1)-petalled rose? —METS501 (talk) 06:53, 6 April 2007 (UTC)

I think you may be interpreting WP:NOR a bit too literally, Mets. The real issue is not about "advancing a position" but rather about the "unpublished" part. (See WP:ATT instead of WP:NOR perhaps.) At any rate, this would be a better issue for the talk page for the article itself. VectorPosse 16:52, 6 April 2007 (UTC)

It would be very silly to call such a thing "original research". Michael Hardy 23:13, 7 April 2007 (UTC)

Then Wikipedia is very silly. What about versions that miss the even petals for originally "odd-petalled" roses (which might be called "she-loves-me roses"), or roses with only every third petal, or only the petals whose index is prime? Or roses with petals of different sizes? The variations on functions that can be invented have no limits. Fortunately, the prohibition on OR is a clear criterion by which we can keep such products of unbridled inventivity out of Wikipedia.  --Lambiam^Talk 00:25, 8 April 2007 (UTC)

I think you hit the nail on the head when you said Wikipedia is silly. However, I think we have to do what we can to keep Wikipedia usable for those of us interested in the non-silly and not-so-silly portions. I could write a (set of) article(s) on the multiplication table of of numbers in base 2007 (Well, I couldn't physically type it, but theoretically a computer could do it.) The resulting article wouldn't necessarily be original research excepting creating of a notation for numbers in that base, but it wouldn't be notable either, because the results are trivial.

Hehe, it looks like I've just created new policy for Wikipedia. Wikipedia is not a multiplication table. It is not a Rainbow Table either.Root⁴(one) 03:51, 9 April 2007 (UTC)

The formula above is yet another excellent reason why vertically stacked fractions should not appear in superscripts. Consider:

$r=\cos(k\theta )(-1)^{\displaystyle {\left\lfloor (\theta -\pi )/\pi \right\rfloor }}.\,$

Michael Hardy 21:08, 6 April 2007 (UTC)

Thanks, but either way, there's objections, and I don't want to add it if people don't want it. —METS501 (talk) 23:33, 6 April 2007 (UTC)

Double integral and Multiple integral

Anyone think that the double integral article should be merged into the multiple integral article? The triple integral article already redirects to multiple integral.--Jersey Devil 02:52, 9 April 2007 (UTC)

To be sure, multiple integral is a lot more detailed, but very general + many details ⇒ intimidating (frequently). I think that the double integral article can be considerably improved, with more geometric treatment and little or no measure theory (at the moment, it reads more like misconceptions about double integral). Arcfrk 04:27, 9 April 2007 (UTC)

Currently the double integral covers basically the same as Fubini's theorem but expressed in such a way as to cause uncertainty and doubt in any freshman. Multiple integral has similar problems, this long page could be shorterened by moving the majority of content for polar, spherical and cylindrical coordinates into their respective articles. I've now made double integral a redirect, but there is scope for expanding it. --Salix alba (talk) 10:40, 9 April 2007 (UTC)

I don't think that was appropriate. Multiple integral is not very user-friendly. Double integral needed some better introductory material, but if you are just in need of a basic introduction to the calculus of multiple integrals, you don't want generality, you want some idea of the picture and the reasons why two definite integral operations should commute. Charles Matthews 07:31, 10 April 2007 (UTC)

History alteration

Something bizarre and troubling has come to my attention. I was looking at the article on classical modular curves and saw that two superscripts were closed with ^{instead of}. I fixed the problem, but was puzzled that something with such dramatically visible consequences had previously escaped notice. So I checked the edit history, which showed the problem had been there for a long time, flying under the radar of a number of seasoned editors. This struck me as odd, but I moved on. But just now, I found the same phenomenon with a subscript tag in an article, area of a disk, I have worked on and scrutinized repeatedly. Here, another editor did the fixing. The history claims a subscript tag has been missing for some time. I don't believe it; I'm sure the presented history is false.

False histories:

• classical modular curve
• area of a disk

I don't know what the source of this may be, whether a software glitch or deliberate foul play; but we really need to be able to trust histories. At the moment, I do not. --KSmrq^T 03:44, 9 April 2007 (UTC)

Essentially the same "disclosures" occur in Talk:Area of a disk, where they are at least as visible. It is hard to imagine David Eppstein not noticing the diminished appearance of this contribution of his.  --Lambiam^Talk 04:11, 9 April 2007 (UTC)

Huh. Weird. The same thing happened on the Hilbert matrix article. I wondered how that could've escaped so many people's attention for so long... Lunch 04:16, 9 April 2007 (UTC)

Must be some bizarre server problem. I just saw another example today, at crystalline cohomology. It has already been corrected, but I am absolutely certain that the problem (unclosed sub) wasn't there whenever I had looked at it since the article was created, and the last time was less than a week ago. Arcfrk 04:44, 9 April 2007 (UTC)

So the server is taking the slashes out of the close tags? Weird. I wonder if it's happening with any tags other than sub and sup...ref could be particularly disasterous since if the references tag is inside a ref it won't ever get expanded. And yes, I imagine I would have noticed the shrunken text in that comment, had it been like that before. —David Eppstein 04:54, 9 April 2007 (UTC)

(edit conflict) This is probably related to a recent update of HTML Tidy, announced at Wikipedia:Village pump (technical)#Tidy upgraded. It seems like the old version of HTML Tidy repaired stuff like a<sub>1<sub> by replacing the second <sub> tag by a close tag, while the new version does not do this. -- Jitse Niesen (talk) 04:58, 9 April 2007 (UTC)

So does this mean that x^yz nested superscripts will start working? Good news if so! —David Eppstein 05:12, 9 April 2007 (UTC)

We have had a workaround for the nesting, using a <span> around the inner script. But if Jitse is right, the errors have been in the source the whole time, silently corrected. --KSmrq^T 06:39, 9 April 2007 (UTC)

Should we ask a bot owner to list pages with <sub>...<sub> or <sup>...<sup> that were previously automagically repaired, so that we can fix problems now no longer covered-up?  --Lambiam^Talk 07:20, 9 April 2007 (UTC)

I think that Jitse is correct. The errors have been there all along, but were hidden by bugs in the processing of html. Notice also that where previously tags terminated automatically at the end of a paragraph, now they do not. A user had trouble with the "small" tag on the signature of Signpost not terminating any more and affecting the rest of his user talk page. JRSpriggs 11:11, 9 April 2007 (UTC)

Yes, I agree. I often make the mistake of missing out the slash in a closing sup or sub, but was previously forgiven by the generous HTML tidying code. Now it is not so generous, we should all go back to articles we have edited and check them for mistakes! I made this mistake several weeks ago at affine connection for example, but only discovered and fixed it today. Geometry guy 16:50, 9 April 2007 (UTC)

I can recommend the editor wikEd, which helps saving time by inserting sup and sub and much more. For those (like me) who do not crave for the command line text editor atmosphere, this nice tool creates some comfortable editing environment. Jakob.scholbach 17:37, 9 April 2007 (UTC)

Tidying up after the change to HTML Tidy

I'm going to do a database dump search and find all instances of <sup>......<sup>, <sub>......, ......, and <sub>....... Note that some of these might actually not be problems (like if the user intended xyz) but if they're listed by a bot then we can go through them and check. —METS501 (talk) 17:59, 9 April 2007 (UTC)

For completeness, include <sup>...<sub> and <sub>...<sup>.  --Lambiam^Talk 18:34, 9 April 2007 (UTC)

OK. I'm doing each case separate, because it's easier that way, and I'll include those two. It looks like it's very successful, almost all the articles it's catching have the problem, which is thousands and thousands of articles, unfortunately. I'll post when I'm done making the list. —METS501 (talk) 18:49, 9 April 2007 (UTC)

Also, the newest dump is 7 days old, so it's catching many that've already been fixed (it caught the versions before these edits, for example) so I'm going to have to parse the live versions of pages before presenting the list. —METS501 (talk) 18:52, 9 April 2007 (UTC)

What a hero METS501 is! Things like this are what make WP so great! Geometry guy 18:59, 9 April 2007 (UTC)

LOL. First set of data done at User:Mets501/Pages that need to be fixed. —METS501 (talk) 19:31, 9 April 2007 (UTC)

OK, two sets done; that's about 900 pages to work with so far. I'm supposed to be on Wikibreak now, so I can't spend any more time, but that should be enough for the time being. —METS501 (talk) 19:48, 9 April 2007 (UTC)

Since I see that a lot of the subscript problems involve chemical formulae, I left a note over on Wikipedia talk:WikiProject Chemistry describing the problem and pointing to Mets501's page. Perhaps some of the people there can help as well. —David Eppstein 20:23, 9 April 2007 (UTC)

Perhaps we should make a separate list of problematic maths articles (the intersection of the list produced by METS501 and the list of mathematics articles).  --Lambiam^Talk 20:28, 9 April 2007 (UTC)

I fixed a very small handful of /sup errors (often mine) in mathematical articles. It would be good to update this problem from time to time, even if it requires us to drag the magnificent user Mets501 out of wikibreak. Geometry guy 20:47, 9 April 2007 (UTC)

I've updated the list. I can do this once or twice a day if that's the kind of update that you mean. —METS501 (talk) 21:43, 9 April 2007 (UTC)

Wow, fantastic! Once a day (or every few days) would suit me fine! Lets hope the chemists can sort out their stall too. Geometry guy 21:54, 9 April 2007 (UTC)

OK, I've rewritten the program, so all I have to do is press one button and the bot updates the list :-) I can run it often, because it's no work for me! [26] —METS501 (talk) 22:12, 9 April 2007 (UTC)

Good work so far. Some questions: Does the consolidated list include all combinations of subscript and superscript? Can we have a consolidated list intersected with mathematics articles to let the chemists fend for themselves? How do I prevent an article with properly nested script tags (x^{y^z}) from being listed every time? The numbers do not seem to indicate the number of errors; can that be changed? Can we get a display of a little text surrounding each error, so we don't have to search through twenty tags to find one? --KSmrq^T 23:21, 9 April 2007 (UTC)

Thanks. Unfortunately, I have very little time now; not nearly enough to invest in writing code much more complex than it is now. It looks like the list is being weeded through quite fast now by Beetstra with AWB, and the rest we'll have to be done by hand. I'll look into putting in some surrounding text, but I'm not sure how quick it would be do that. If you remove a page from the list, the bot won't add it back, so if it's on the list in error, just remove it. The bot has two functions (at the moment): it can go through the database and check for <sup>...<sup> and <sub>....<sub>, and it can go through each page listed at User:Mets501/Pages that need to be fixed and check if it still has a syntax error. I'm going to expand the first function soon to include other syntax errors as listed above. —METS501 (talk) 00:10, 10 April 2007 (UTC)

Citizendium content

Just to bring back an old discussion about content from Citizendium, the Special:Export page works on Citizendium to get the wikicode of any page. For example, to get the code of their Mathematics page, visit http://en.citizendium.org/wiki/Special:Export/Mathematics. Not in ideal form, but it's a way. —METS501 (talk) 00:01, 10 April 2007 (UTC)

The copyright of these pages is, unfortunately, still unclear. It would be prudent to avoid copying material from CZ to here until CZ gets their act together. CMummert · talk 00:52, 10 April 2007 (UTC)

Definitely. I was just pointing out that we actually don't need registered users there to get their source code. —METS501 (talk) 03:11, 10 April 2007 (UTC)

Institute for Mathematics and its Applications

In one of the most idiotic edits I've seen in a long time, User:The Kinslayer, who seems to spend most of his efforts on topics of no importance, marked Institute for Mathematics and its Applications for speedy deletion on the grounds that it is not important, and did not notify anyone who had edited that page. It was recreated recently. Someone else then deleted it. Michael Hardy 02:40, 29 March 2007 (UTC)

This user seems to have a problem with articles on institutes.[27][28][29]  --Lambiam^Talk 07:03, 29 March 2007 (UTC)

This user is not alone. I wrote a stub on Fachinformationszentrum Karlsruhe which got marked for speedy deletion by Realkyhick the next minute. Now that's itchy fingers. Jmath666 07:47, 29 March 2007 (UTC)

It is an unfortunate consequence of the large number of nonsense pages created each day that, when creating a stub on a person, company, institute, etc., one must immediately add references to assert notability or the article is likely to be tagged for deletion almost immediately. The number of math related articles created each day is far less than the number of nonsense or non-notable pages, so we can't really hope for some sort of special treatment. One solution is to write such articles in a subpage of your user page and move them into place once they are basically done, even though this violates the basic idea of collaboration on the wiki. CMummert · talk 11:27, 29 March 2007 (UTC)

Sounds like these human spam filters need their Bayesian statistics adjusted. The odd thing is, ever since I began bringing up random articles frequently, I've been struck by the fact that almost all are a paragraph or two on an obscure topic. So this "shoot first" approach, while an understandable reaction to garbage, is tainted by ignorance. A town of 300 people: no problem; a minor sports figure: no problem; a major mathematics institute: kill it. The garbage is a cancer, and these people want to feel useful. But, as so often happens, the "cure" has damaging side-effects, sometimes worse than the disease. --KSmrq^T 14:32, 29 March 2007 (UTC)

I recently exchanged a few pleasantries with Realkyhick about his shoot first and ask questions later approach to new articles. I notice that he's a member of the New Pages Patrol. He also ignores the guidelines for that process with some regularity. I suggested that he at least look at the page history before tagging an article with a speedy delete tag, but he doesn't seem inclined to accept that suggestion. Type A personality, I guess. DavidCBryant 15:22, 29 March 2007 (UTC)

Fachinformationszentrum Karlsruhe happens to be marginal (not a major mathematics institute like IMA) but the original article did indicate why it was notable, even if the article was very short. It took some speedy expansion (which I really did not plan on doing right at the time) to keep the trigger happy patroller off. Apparently it is not clear what it takes for an article to be a valid stub. Well, the lesson is just keep the red tags in and do not go the next step unless one is ready to invest some work right at the moment. Jmath666 15:41, 29 March 2007 (UTC)

It seems that the root of the the problems discussed here is that the speedy deletion is too speedy - both the tagging and the admin action. Per CSD: The word "speedy" in this context refers to the simple decision-making process, not the length of time since the article was created. There should be a reasonable time required for both. There is something vague about that in CSD but I could not find mention of some mandatory wait period anywhere. There should be one. Jmath666 23:14, 29 March 2007 (UTC)

There are, I think, good reasons for speedy deletions to be speedy. The problem is not the existence of speedy deletions, but rather someone abusing the speedy deletion process. The only criterion I can see in WP:CSD that might fit is A7, "does not assert the importance or significance of its subject". That is, even when you write a stub, you have to explain what is notable about the subject; why is it important enough to be in WP? E.g. in the current article "largest single mathematics grant the NSF has ever awarded" seems to be enough to counter that criterion. I don't know how to access the previous versions in order to tell whether similar language was present in the deleted versions, but if it was, they shouldn't have been deleted. I don't know what the process is when one feels that an admin has been consistently abusing speedy deletion, but I assume there is some appeal procedure available. —David Eppstein 23:52, 29 March 2007 (UTC)

I added that fact because I thought it was interesting, not really to establish notability. It was not present in previous version, which also had no references except the external link. I added the reference to the SIAM article to assert notability. WP:notability doesn't mean notability - it means "discussed in multiple, independent reliable sources", so the only way I see to assert notability is to include such sources.

As for appeal, you could I suppose go to WP:DRV, or you can ask a friendly admin to give you a copy of the deleted version, add some content, and recreate the article. There are about 20 admins associated with WP:WPM, which is about 1 per 800 articles, a better ratio than WP as a whole. CMummert · talk 00:35, 30 March 2007 (UTC)

You can't know what should be considered notable and what should not without familiarity with the field. It seems to me those who were involved in the present case disregarded that fact, which I would think would be obvious. Michael Hardy 00:00, 30 March 2007 (UTC)

Of course you can't tell what is notable and what is not without some knowledge, but it's not too hard to determine whether an article asserts notability (in this case, importance or significance), which is the speedy deletion criterion. Articles about even obviously notable subjects will get deleted if they do not include anything telling the reader what their importance is. The only thing that could possibly be interpreted as an assertion of significance in the original article was that the IMA was a body with academic aims associated with a particular university. That description does indeed suggest that the organisation could be quite significant and I wouldn't list it for deletion, but I can't really blame anyone for thinking there was no claim to importance. JPD (talk) 10:01, 30 March 2007 (UTC)

Now that the history has been restored, we can look at what was there before deletion. Two things strike me. One, behind the scenes, is that the article has a long history. Two, the article has a link to the organization's web site. It would take less than thirty seconds to check both of those, which should give more than enough information to see that a "speedy" tag was wrong. Note I am assuming a tagger and an admin who know nothing about the standing of the editors who touched the article, and who know nothing about the mathematics world. Was it a stubby, lackluster article? No doubt. Was "speedy" appropriate? No way.

Here's what the WP:SPEEDY page says, at the top:

• Before nominating an article for speedy deletion, consider whether an article could be improved or reduced to a stub; speedy deletion is for cases where an article does not contain useful content. Note that some Wikipedians create articles in multiple saves, so try to avoid deleting a page too soon after its initial creation. Users nominating a page for speedy deletion should specify which criteria the page meets; it would also be considerate to notify the original author.

From this lead paragraph of three sentences, not one was properly followed. I frequently look at random articles, and the one that I just hit is HaShevet. Compare it, especially what it explicitly asserts (or fails to assert) about notability, with the IMA article at the time of tagging and deletion. So forget the CYA, which is not very convincing. The typical catastrophic failure involves a sequence of things going wrong; here, article, tagging, deletion, and response.

From Barlett's Familiar Quotations:

• "Thus grief still treads upon the heels of pleasure;
  Married in haste, we may repent at leisure." — William Congreve, The Old Bachelor, Act V scene 1.

Sum the time spent by multiple editors in response to the hasty deletion and compare to the time necessary to do the right thing in the first place. Need I say more? --KSmrq^T 17:28, 31 March 2007 (UTC)

Unfortunately this IMA article *did* look like a typical Speedy candidate when it was nominated. It said in effect, 'There is this institute at University of Minnesota, it exists, and it's wonderful'. Its only reference was its own web site, and it had no links to other WP articles except to the Univ. of Minnesota and another institute with a similar name. There was no mention of NSF or SIAM in the version nominated; certainly nothing about the largest NSF grant ever.

A mathematics editor described the tagging as vandalism; I think that was unfair. (See User_talk:The_Kinslayer#IMA and User_talk:Coredesat/Archive_7#IMA). Speedy deletion does not poll the universe to see if the deletion is wise, it just goes and does it. Such deletions are easily reversed if someone complains. The clue that the speedy-tagger missed was 'mathematics of the highest caliber'; I guess that should have registered as the claim for notability. I suggest that the phrase 'idiotic edits' (which sounds like a personal attack) be removed from the above comment. EdJohnston 01:19, 5 April 2007 (UTC)

I agree that there is an overreaction here. Vandalism is a serious charge, alleging more than just simple ignorance. I think it's best to put the best front possible when engaging people on their talk pages as a representative of a WikiProject. There is a problem of ignorance here though. It ought to be addressed in a forum for people like the new article and recent changes patrollers. A lot of these anti-cruft policies like CSD A7 were created for expediency in deleting non-notable people and groups. One thing failed to be understood by these people is that an institute at a major American research university is already far more notable by its affiliation than an institute in say, Elbonia, just like someone who wins an AMS prize is automatically far more notable than somebody who wins some Elbonian prize. (Or even a full professor at an American research university is probably already far more notable than a winner of said Elbonian prize, even though the latter may look more like an assertion of notability to the ignorant.)

where the heck's Elbonia and why we hatin' on the Elbonian folks? Mct mht 12:52, 11 April 2007 (UTC)

Elbonia is a very backward country (6th or 7th world) in the cartoon universe. :) JRSpriggs 08:11, 12 April 2007 (UTC)

In addition, a fact which may look like an assertion of notability to someone unfamiliar with the mathematical world may in fact be completely irrelevant to what makes a well-written, informative article; hence people used to writing good articles will not include such assertions. Rather than rail about this, it is more productive to let the patrolling community know. In fact, if you go to these pages, you will find they do have guidelines such as don't speedy an article too quickly after creation, don't be too hasty in prod'ing, etc. People who do a bad job of speedying articles are not representative of the best of the patrolling communities, and we should not declare all-out war on these people. Instead, let's work with them and straighten this out pleasantly, by say, discussion at Wikipedia:RC_patrol and Wikipedia:New_pages_patrol.

The real problem in this instance seems to be that the wording of CSD A7 ("An article about a real person, group of people, band, club, company, or web content that does not assert the importance or significance of its subject.") is problematic. In the past, I've had to argue with people that an article stating "This guy is really, really important. He lives on 3213 Wakefield Street, Ohio." does not assert notability. It seems that fewer people think of this as such an assertion nowadays, most having come to the realization that said assertion should satisfy a condition such as plausibility. Actually, it's funny, but at one point I'm certain CSD A7 said it should be "plausibly assert", now it doesn't! (Some of these points have been raised at Wikipedia_talk:Criteria_for_speedy_deletion#CSD_A7_again; I think it's a good idea to join this discussion quickly and make our views known in order to avoid this kind of situation in the future) --C S (Talk) 11:13, 11 April 2007 (UTC)

Proof sketch for Gödel's first incompleteness theorem

This article was created a few months ago and has sat mostly untouched for two months. As it stands, the article has problems visible from even a cursory reading. I was about to start working on it, but first I want to get a sense of whether this article belongs on WP at all. On the one hand this is a famous and important result that is covered in practically every text on mathematical logic. On the other hand, the proof can be found in practically every text on mathematical logic, so sketching the proof here only duplicates what is already available (and probably better) in other locations. CMummert · talk 22:42, 4 April 2007 (UTC)

Would it be much work to fix it up? It's kind of entertaining that the proof is here, and a person can jump into it and at least pretend that they understand it. Adding a list of books that explain the proof more thoroughly would certainly be useful as well. I see on the Talk page that you left some suggestions for the creator of the article, and he hasn't followed up. EdJohnston 22:57, 4 April 2007 (UTC)

It looks like a lot of work to me! For one thing, it is dangerously close to WP:OR. The use of three digit codons follows Hofstadter, but a different coding is used and is unsourced. It is also too technical, and the English is not great. At the moment, I find the proof sketch in the main article more helpful. In particular, I think it is better not to emphasise a particular choice of coding. Geometry guy 11:43, 5 April 2007 (UTC)

To fix this article would require a great deal of effort. The correct proof has some technical, subtle parts that take care to explain. I think the article is too vague, not too technical. For examples of problems in the current article, look at the paragraphs numbered 1, 6, and 7. CMummert · talk 11:53, 5 April 2007 (UTC)

I have seen this discussion only now, indeed English is not my first language, and I'll see what I can do regarding your comments. Anyway if the article is too vague for some and too technical for others, maybe that means that it's just in the corect level for others? no original research was done here, and the 3 digit codon I used is borrowed from the "Goedel Esher Bach" book though I used a different coding exactly because the choice is not important - surely you wouldn't call this WP:OR. There's also a link to the formal proof. Since this theorem atracts a lot of attention from people with only limited mathematical background, it seems to me nice that there's something they can read which would hopefully give them a clue about how the theorem is proven.Dan Gluck 19:51, 5 April 2007 (UTC)

Editors here will be uncomfortable if they don't think your article is correct. Do you have the background to fix the subtleties mentioned by CMummert? I suppose you could skip the hard parts if you left a pointer to a book that supplied the missing material. But then the fact that your coding is different might confuse people who had to switch to the book. EdJohnston 01:35, 6 April 2007 (UTC)

I thought the problem wasn't that it's incorrect, but that I skipped some technical parts. Since there's a pointer to the full proof on the web, and (I think) I mentioned all the places where I have done so, I don't see a problem. The proof on the web doesn't use a coding, since it does not need to specify one explicitly; the coding I have given is only an example for pedagogical purpose, as in Hofstadter's "Goedel Esher Bach" book. I would love to use the coding in that book, but I don't have it, and anyway I'm not sure it's permitted by copyright law.

Anyway perhaps I missed it, but all of CMummert's specific comments (in the article's talk page) are related to the form of the article - he suggests deviding it to sections, adding more links etc. I saw no content-related specific comment. Dan Gluck 19:54, 6 April 2007 (UTC) Anyway mathematical logic is not my field of expertise, so if it is yours, and you think the article is incorrect and cannot be repaired, feel free to erase it :( Dan Gluck 20:00, 6 April 2007 (UTC)

I added some comments on the article's talk page about the content. It's not the content of this particular article that led me to ask a question here; I am certain that this particular article can be fixed up, and i was about to do so myself. The real question is whether an article entirely devoted to a proof is acceptable. I didn't want to spend a while making changes only to have the article is nominated for deletion. Personally, the more I read this sketch the more I like it. CMummert · talk 20:16, 6 April 2007 (UTC)

I'm not a lawyer, but I believe it is legitimate to use Hofstadter's coding as long as his book is clearly cited (and this has to be done anyway to source the approach taken by the article). This would require some work, however, because Hofstadter's coding uses the successor function to define numbers, instead of the (rather nice) base 10 coding of the article. Perhaps a compromise coding would work better (although I still worry a bit about OR - unusually for me, since I think explaining things in new, interesting and engaging ways is exactly what an encyclopedia should do). Anyway, I have GEB and would be happy to contribute the relevant information. Geometry guy 15:58, 9 April 2007 (UTC)

Well, the criterion for OR is this WP:OR#What_is_excluded.3F. I don't think the article satisfies any of the conditions there. If everybody agrees that there are no mistakes, and it is a rephrasing of the proof (hopefully in a more understandable way) with some technicalities overlooked, I don't think it's OR. Dan Gluck 20:52, 12 April 2007 (UTC)

Redundant articles

Hi. I noticed when adding a link somewhere to Bijection that we have individual articles for Bijection, injective function and surjective function, as well as an article called Bijection, injection and surjection. Is this the optimal way to cover these topics? It seems redundant to me. At the least, should bijection be renamed to bijective function, for consistency? -GTBacchus^(talk) 18:52, 9 April 2007 (UTC)

I think your suggestion to rename is spot on to make the titles at least parallel. I would say that the Bijection, injection and surjection is redundant, except it's actually very nicely written. For now, I've linked the three concepts in that article to their respective pages, and I've added some {{main}} templates in each section. I'm interested to hear other opinions on this. - grubber 19:04, 9 April 2007 (UTC)

A quick review of the talk pages shows that this has been discussed several times. I made some comments here. CMummert · talk 21:13, 9 April 2007 (UTC)

It appears that, while opinions differ on what to do with the joint article vis-a-vis the separate ones, there is at least a broad agreement that bijection should be moved to bijective function, for consistency with injective function and surjective function. I see that this point has been raised at Talk:Bijection#Rename?, but not much came of the discussion. I've commented there; perhaps it would be appropriate to do an "official" move request through WP:RM, or we could just agree to do it because it makes sense. -GTBacchus^(talk) 21:27, 9 April 2007 (UTC)

I don't think that you will be able to do the move yourself, because of edit history at the redirect page (I'd be curious to know if you can, in fact). In any case there are quite a few admins in the math project, so you won't need to go to WP:RM to get this done. Let's wait a little while to give people a chance to object, though. CMummert · talk 21:42, 9 April 2007 (UTC)

(edit conflict) While opinions have differed in the past, perhaps it is time to revisit the idea. I can't imagine anything doing a search and lading on Bijection, injection and surjection. I agree, though, that the material there is good. Is there any reason this good stuff can't be moved to each of the three separate articles? VectorPosse 21:45, 9 April 2007 (UTC)

(reply to CMummert) I'm one of the admins who monitors WP:RM and moves pages daily, so that part's not a problem. The only reason I suggested going through RM is that it sets up a somewhat official discussion area, and that's often a good way to bring people with opinions out of the woodwork. It's no problem at all for me to set up a discussion, but at the same time, it's really not a formal necessity. -GTBacchus^(talk) 21:48, 9 April 2007 (UTC)

Sorry about that - you weren't on my list of admins who contribute to the math project. I think that a formal process isn't warranted if there is clear consensus for the move. Renaming pages isn't supposed to be a big deal. I went through the page history of the destination and it has only ever been a redirect. CMummert · talk 22:06, 9 April 2007 (UTC)

No worries; most of my contributions here aren't math related. You're certainly welcome to contact me anytime you need an admin who's mathematics-literate. For this page, I think we'd be fine moving it after allowing a day or so for anybody to raise an objection. (It would probably be fine to do it right now, but it can't hurt to sleep on it.) Because I may not be online tomorrow, I've gone ahead and deleted all but the top redirect at bijective function, so now anyone can carry out the move. -GTBacchus^(talk) 22:16, 9 April 2007 (UTC)

I think redundancy can be discussed, but I object to changing bijection, which is definitely used, although, perhaps, not as much as bijective map, to bijective function, which is very contrived sounding and not at all common. See my comments here. Arcfrk 04:02, 10 April 2007 (UTC)

Huh, now that you say that, I guess I have heard "bijective map" more than "bijective function". Should we be talking about moving the other two articles to injective map and surjective map? I think all three should be the same, and injection isn't available. -GTBacchus^(talk) 04:48, 10 April 2007 (UTC)

I don't really care, because there will be redirects, but I think that "map" is a poor choice because it has too many real world meanings. "Function" is much more clear, and the bare word "Bijection" is pure jargon and thus unconfusing. CMummert · talk 00:45, 11 April 2007 (UTC)

I see nothing wrong with injection (mathematics) and surjection. Septentrionalis PMAnderson 23:42, 11 April 2007 (UTC)

Yeah, that mirrors common usage the best. -GTBacchus^(talk) 23:44, 11 April 2007 (UTC)

A question about plagiarism

I recently ran across some copyright violations, and read the policy. I think I understand how to go about cleaning those up. This article is different. It's an outright copy of this newsletter article. Interestingly, there's no copyright notice on the isi web site – or at least, I couldn't find it. Also of interest, this article was contributed by User:Pdagum, who one might reasonably suppose to be a relative (son Paul?) of Prof. Dagum.

Anyway, I'm unsure what to do about this one. It's an "in memoriam" article, quoted verbatim. As such it certainly doesn't sound very encyclopedic. Suggestions? DavidCBryant 14:40, 12 April 2007 (UTC)

It sounds like a violation to me- copyright is assumed unless specifically released. So "no copyright notice" isn't good enough, we need a specific statement that it is free content. Staecker 14:48, 12 April 2007 (UTC)

I would remove the copyrighted text, leaving a stub, and leave an explanatory message for the article's creator. You could try {{uw-copyvio}} along with an explanation of the specific situation. CMummert · talk 14:56, 12 April 2007 (UTC)

Projective space - painting of Dürer

Does someone know the title of the painting by Albrecht Dürer (I guess, not absolutely sure though), which shows a projection a smaller shape onto a bigger canvas? I know, the description is very vague... The image has some geometrical interest, I'd like to put it to projective space (if it is available somewhere). Jakob.scholbach 04:51, 13 April 2007 (UTC)

The one most often used is this picture of a lute, from Dürer's Underweysung der Messung mit dem Zirkel und Richtscheyt, Nuremberg, 1525. However, another choice is the reclining nude from the same work. I would expect that an image scanned from the book is free of copyright restrictions, but that's a legal question, and the scans I have seen on the web are not ideal. --KSmrq^T 07:41, 13 April 2007 (UTC)

Strange article

Any hope of evolving Mathematical landscape into something encyclopedic or shall it go straight to AfD? --Pjacobi 13:15, 8 April 2007 (UTC)

I think the point of the article is something called the "Mathematical landscape conjecture". The author of the article is new here, so maybe asking him/her for a reference is a good first step. CMummert · talk 14:14, 8 April 2007 (UTC)

Just saw this before coming here. Tagged several statements that seemed speculative and unsourced with {{cn}}. But if it doesn't improve, I'd likely vote Delete in an AfD. —David Eppstein 16:38, 8 April 2007 (UTC)

Strange indeed. Although there is a game some theoretical physicists play with speculating about why certain numbers appear, we can say things about any number. For example, 1728 (which is 12³) is a very special number that is not listed. As written, this article is hardly more than numerology. --KSmrq^T 21:21, 8 April 2007 (UTC)

I posted a message on User talk:Qloop. Let's see what the author has to say. -- Jitse Niesen (talk) 02:59, 9 April 2007 (UTC)

This one has been struggling me somewhat. Although it is not very far from my research area, I have not heard of the "mathematical landscape", and the "mathematical landscape conjecture" seems to be not only unsourced and very vague, but also complete nonsense. I tried to source this article myself, but the best I have found so far is one of John Baez's nice pages. I think I know what the article is trying to say (and there is something interesting to say here), but at present it is clearly in the AfD firing line, and is a magnet for a whole load of numerological speculation. For example, the "26 dimensions" section has already attracted the comment that there are also 26 sporadic groups, which is a completely unrelated fact (as far as I know from sources to date). Geometry guy 17:07, 9 April 2007 (UTC)

I've never heard it given the explicit name of "mathematical landscape conjecture", but I'll affirm that it is the defacto deeply held tenet held by those theoretical physicists who have wandered off to string theory and beyond. After the fantastic successes of General Relativity, Standard Model and QCD, and the near-misses of Kaluza-Klein theory, supersymmetry and etc., a large part of the theoretical physics community decided that surely, the Theory of Everything would be immediately obvious, if they just knew only a tiny little bit more math, or that, at least, if nothing else, they'd be the second person on the planet to figure it out after Ed Witten did. The near-miss of Monstrous Moonshine only affirmed this belief of the congruence of mathematical landmarks and physical reality: there was 3 or 6 or 12 months or so, in the mid-1980's, where a lot of physicists honestly, truly believed that the monster group really was the group that described the known universe and everything in it. A lot of ink was spilled. Well, here we are 20 years later, and we've got doodly-squat to show for it. The experimental physicists are all pissed off and are saying that the theoreticians are shirking their work and have abandoned them, and string theory is theological mumbo-jumbo. But the core belief remains: if we can only find that one magic mathematical expression, it will be everything, and of course it'll be a Lie group, and of course it'll be p-adic, and of course it will have a j-invariant, and a moduli space, and etc. woven into one beautiful whole. Why, in fact, the ratio of the strong/weak/electric/gravitational forces are in the same proportion as the first four Mersenne primes! Didn't know that? Well, there are string theory papers out on ArXiv that explore this numerology... linas 00:04, 10 April 2007 (UTC)

To be clear, I'd probably vote to delete this article, since it does seem to be OR. linas 00:30, 10 April 2007 (UTC)

Perhaps the article could be saved by changing the focus to the sociological phenomenon described by Linas in his message here. JRSpriggs 07:05, 10 April 2007 (UTC)

Call me a pessimist, but writing about this kind of sociological stuff is difficult and will no doubt be easily prey to OR, lack of citations, and just generally crap. We already have great difficulty with articles about mathematical education (which can be readily sourced and is written quite frequently about). Who's ready and qualified to change this article anyway? --C S (Talk) 11:59, 15 April 2007 (UTC)

Help the Physics Project

The level of activity at the physics project has fallen way off. See Wikipedia talk:WikiProject Physics#Is this WikiProject moribund?. If any of you have an interest in physics, but have not been paying attention to it lately, now would be a good time to get involved. JRSpriggs 07:15, 10 April 2007 (UTC)

I don't think emphasising high-profile departures is very helpful. Charles Matthews 12:10, 11 April 2007 (UTC)

I do not think that killing the messenger is very helpful. JRSpriggs 08:13, 12 April 2007 (UTC)

I wasn't intending to. I was commenting on the content of that discussion. Charles Matthews 11:44, 15 April 2007 (UTC)

Requested articles

Many of the requests currently listed on Articles requested for more than two years seem to be mathematical ones. The requests on this page are those which have been unfulfilled for the longest time, and we therefore tend to treat them with a higher priority than those requested only for one year and the other request pages. If any members of this WikiProject have sufficient knowledge and access to sources to write a good stub on one or more of these topics, it would be much appreciated. Thanks – Gurch 10:31, 11 April 2007 (UTC)

Those are almost all logic articles; more specifically set theory. Charles Matthews 12:54, 11 April 2007 (UTC)

All but one of the titles listed on Wikipedia:Articles requested for more than a year#Mathematics are also on the > 2-year list, and are moreover conveniently selected on being maths topics. (The extra title looks more like a physics topic to me.)  --Lambiam^Talk 15:16, 11 April 2007 (UTC)

Many of them can just be redirects. Take the topmost example from the 2 year list, amenable set, for instance. I was, just the other day, going to write an article on the Gödel, Jensen, Lévy etc. constructions (none of which exists as an obviously named article), but then I soon found that an article already exists on the constructible universe. It is pretty unlikely that we will be able to write a feature length article on amenable sets (without abandoning all pretence to being a general encyclopedia, that is), but we should certainly be able to do a better job of presenting the various independence results— if only to redirect key concepts to more comprehensive articles. — Kaustuv Chaudhuri 16:50, 11 April 2007 (UTC)

These are lazy answers :) If e.g. amenable set should be a redirect then why not make a redirect rather than just chatting about it? But are we talking about admissible or amenable sets? The first is mentioned in constructible universe, the second is not. After an hour searching, I eventually found a reference discussing the distinction between admissible and amenable sets, but did not understand it. Surely we can do better than this :( Geometry guy 22:16, 13 April 2007 (UTC)

Cheer up geometry guy! I think I finally understood the difference between amenable sets and admissible sets, so I fixed that. I also redirected the redlinks that seem to have something to do with Determinacy to that article. Geometry guy 14:11, 14 April 2007 (UTC)

I'm glad you took some action, but I must say that the end result is not as perspicuous as one wishes. Someone will eventually have to sit down and write some text. I myself must continue to plead laziness for the time being. — Kaustuv Chaudhuri 09:05, 16 April 2007 (UTC)

Category:Mathematicians by religion

At the moment, mathematicians are divided by religion in Category:Mathematicians by religion. Analogous categories for many other professions (including in many scientific fields) have generally been deleted, mainly because religion is largely irrelevant to the given profession. Some people have defended these categories as being used specifically for clergy or devoutly religious, but they are rarely used that way in practice, as the category names leave open the possibility that someone will use these categories to identify anyone who is a mathematician of a given religion.

I was wondering whether these categories had the support of WikiProject Mathematics or not. If people here generally disapprove of these categories, then I can nominate them for deletion. On the other hand, if people really want these categories, then I will leave them alone.

Could other people here please comment? Thank you, Dr. Submillimeter 15:28, 13 April 2007 (UTC)

I think this is an example of categorization gone astray. It is not that important what a religion a mathematician had. One's got to pick and choose which are the most relevant categories to add a person too, and I doubt this qualifies. Oleg Alexandrov (talk) 15:38, 13 April 2007 (UTC)

Classifying G. H. Hardy as an atheist is probably harmless; it is one of the few notable non-mathematical features of his character. Pity the article doesn't mention cricket. Extending this, even to Erdős or Russell, is very doubtful; and since the whole variety of category is normally a form of nationalism, bad for Wikipedia. Septentrionalis PMAnderson 16:39, 13 April 2007 (UTC)

This category certainly doesn't have my support: it looks like a case of overcategorization. However, there is a potential minefield with the subcategories here, and I wish Dr. Submillimeter good luck in finding a path through it. There is probably little problem with the deletion of the atheist, Buddhist and Christian subcategories, and it seems reasonable to keep Category:Pythagoreans. However, the other three subcategories are a bit more tricky...

• Category:Hindu mathematicians. This is a subcategory of Category:Hindus by occupation. The name of this category suggests the whole tree should be deleted as overcategorization, but in fact most of the occupations listed are relevant to the religion (perhaps the category needs to be renamed). Is mathematics relevant to Hinduism or vice-versa? Are we already well enough served by Category:Ancient Indian mathematicians and Category:Kerala school, or not? I have no idea.
• Category:Jewish mathematicians. This is even more difficult as there is an argument that being Jewish (especially in the 20th century) does affect ones career and it is therefore much more legitimate to catagorize Jews by occupation. On the other hand, such special treatment for this religion over others has the potential to fuel antisemitism. I would not like to be an arbitrator over this issue!
• Category:Muslim mathematicians. This is probably also an overcategorization, but it belongs to the Category:Muslim scholars tree, which contains several similar subcategories. Should they all be deleted?

Something similar is happening with Category:Women writers. If the overall category is legitimate, is it not legitimate to create intersection subcategories when the category becomes too large? In this project Category:Women mathematicians seems well accepted as is Category:Mathematicians by nationality (or geographical location) and its subcategories. I am not necessarily questioning the legitimacy of this, but where do we draw the line when it comes to closely related issues of ethnicity and religion? Geometry guy 19:04, 13 April 2007 (UTC)

Most other occupation by religion categories are about careers that involve religion (missionary work, religious leadership positions, philosophy, etc.). Some of the remaining inappropriate categories for Muslims (Category:Muslim astronomers) and Hindus (Category:Hindu physicians) are already nominated for deletion. I think some of the other occupation by ethnicity categories have also been deleted; I certainly have not seen any for astronomers. The categories for Jewish people, however, have been treated a bit differently. If I nominate Category:Mathematicians by religion for deletion, I will include all of its subcategories except Category:Pythagoreans anyway (just to be unbiased towards all currently-practiced religions, if nothing else). Dr. Submillimeter 22:30, 13 April 2007 (UTC)

Thanks for this answer. The case for some of these subcategories of mathematicians (especially Jewish and Muslim) is a bit delicate, but maybe we can just see what happens at the CFD. Geometry guy 22:50, 13 April 2007 (UTC)

Spiritual beliefs are not necessarily irrelevant to how a mathematician thinks about the status of mathematical objects and of the infinite -- and this can affect his research as well; not the content of his conclusions, perhaps, but the way he interprets them, and what questions he chooses to study. --Trovatore 01:07, 14 April 2007 (UTC)

I agree that for some people that religion is an important factor in their careers. However, these categories, as they are currently named, will be used for any mathematician who can be described as belonging to a specific religion, regardless of whether that religion had any influence on the person's career. For example, Carl Friedrich Gauss is currently categorized under Category:Christian mathematicians. However, it is unclear from his article as to whether Christianity was at all influential in his career. I am certain that I can identify others.

This is the general problem with these religion/career categories; despite the intentions of a few editors of wanting to restrict these categories to monks or scholar-priests who worked in mathematics, the categories will be used by other people for any articles that appear to describe mathematicians who were a certain religion, even if the religious beliefs had no influence on their careers or thinking.

I will hold off on nominating these categories for deletion a little longer. I would like to see what happens with some currnet discussions, and I would like to see if anyone else comments here. Dr. Submillimeter 22:43, 16 April 2007 (UTC)

Scholarpedia

I stumbled across Scholarpedia today, its a wikipedia type thing written by academics. The coverage seems patchy coving computational neuroscience, dynamical systems[30], and computational intelligence. But the articles that exists seem to be more in depth than here. They have quite a destinguised list of authors Milnor, possible Lonez Conway and Mandelbrot. --Salix alba (talk) 16:43, 14 April 2007 (UTC)

Their articles are under full copyright, by the way [31]. Oleg Alexandrov (talk) 16:54, 14 April 2007 (UTC)

The calibre of authors they're approaching -- and getting to sign up -- for the dynamical systems articles is impressive. Many of the defining people in the field. Their advertising model is interesting too -- matching on-topic ads from Amazon and Google to articles by people of the very first rank in the field. With luck they may generate enough cash-flow that they may actually be able to pay their contributors and their server bills. Which would be a good thing, because Scholarpedia is generating reliable and available online material written by very impressive people, including coverage even for its version 0.1 of topics we still haven't reached. (Dynamical systems has always been a somewhat weak area for WP; but even in other areas they're covering subjects that we don't).

On the other hand, SP is a very different beastie to Wikipedia. Even if their article's were available GFDL (which they aren't), the interesting thing is that I think (and I hope and trust) our eds would want to heavily re-write them -- to make them much more integrated, more accessible for typical readers coming in from other WP articles, more geared to answering typical readers questions, and generally just differently pitched somehow. And it makes me appreciate the real freedom of the anyone-can-edit ethos at WP, because I wouldn't dare touch any of those contributior's articles at SP, even though I'm not sure they all play particularly well together (or are even very well laid out).

So while I'm glad that there's now an online article on Fuzzy Logic by Lotfi Zadeh himeself up at SP, an article on K-S entropy by Y. Sinai, etc., they are useful resources, but they are not actually what I would like to see as articles for WP. Jheald 21:05, 14 April 2007 (UTC)

Link and learn. Charles Matthews 11:47, 15 April 2007 (UTC)

(via edit conflict) One of the things which intrigue me about Scholarpedia, and possibly one of the reasons why they get these top-notch authors, is that they use a traditional peer review system. After the article is written, it's sent to two referees who comment on it. The article is only accepted after the referees give the go-ahead. This is called "initial peer review" in their instructions for reviewers, which say that it allows "authors to list their papers as peer-reviewed in their CVs and resumes". -- Jitse Niesen (talk) 11:52, 15 April 2007 (UTC)

I doubt John Milnor needs to pad his CV! Perhaps it's simpler: survey articles that can be updated and are on the Web probably seem sensible to experts. Charles Matthews 19:37, 15 April 2007 (UTC)

Of course it wouldn't add to John Milnor's CV. I see now that I chose my quote poorly, giving the impression that I think that Scholarpedia's authors contribute to fill their CV. The whole paragraph is "Scholarpedia enforces the same rigorous anonymous peer review process as most printed journals. This is done primarily to insure the accuracy and quality of information, and to allow authors to list their papers as peer-reviewed in their CVs and resumes."

I agree that "survey articles that can be updated and are on the Web probably seem sensible to experts". The question is: why does Scholarpedia attract experts that do not write for Wikipedia (as far as I know)? I suspect that this is partly because Scholarpedia's model (in particular, peer review) is closer to what they are familiar with, while Wikipedia is just a wacky idea. Another factor may be that Scholarpedia actually asks people to write for them. It's harder to decline when you get an email saying "The contributors to the Scholarpedia website have decided that you are the best guy to write this article. Would you please do so?" -- Jitse Niesen (talk) 03:26, 16 April 2007 (UTC)

I think "lack of familiarity" is too kind to Wikipedia. We can look at examples of experts who came here, contributed, then gave up and departed. Suppose Milnor devoted two weeks to writing a survey of exotic spheres, complete with expert insights and a well-chosen bibliography. What would happen to it in the next six months here? Some possibilities:

• A vandal adds an illustration; you know the kind.
• Another vandal blanks the article and replaces it with homophobic hate.
• Some crank inserts a pet theory.
• The inline citation squad splatters it with {{fact}} tags, ignoring the bibliography.
• Any new insights not previously published are removed as violations of WP:NOR.
• Several irate readers demand that the introduction be made more "accessible".
• Some of them, who know nothing of the topic, and little of English, take turns rewriting it.
• A revert war ensues, Milnor is lambasted for WP:OWN, and blocked for WP:3RR.

Need I go on? Do I exaggerate? Wikipedia is not kind to expert scholars. As recently mentioned, topics like general relativity theory fare worse than mathematics, and topics of interest to a wider audience fare worse still.

I wonder if Wikipedia may be like peer-to-peer music; it fills a temporary void. The quality is not great, and we would prefer better offerings, but nothing else was adequately addressing our needs. Where, freely available on the web, do I read about exotic 7-spheres? If nowhere else, perhaps Wikipedia. --KSmrq^T 04:43, 16 April 2007 (UTC)

I agree with the general sentiment, but let's not get carried away. Since you've chosen the exotic sphere article as an example, let's look and consider if any of these things has happened to it. Vandalism? Not really. Crank theories? No. Inline citation problems? No. Accessibility complaints? No. Illiterate ignoramuses revising the page? No (except me perhaps). As for the problems with say, Milnor putting in his new cutting edge research (which has somehow not made it into the literature after all these years...), I doubt he would have any trouble understanding the problems with that; in my experience, mathematicians tend to be good at realizing these things, even those that haven't edited Wikipedia much. Certainly after one of the people who normally edit the page pointed it out to him, I can't imagine Milnor unreasonably insisting on a revert war and being eventually blocked (he seems calm enough in person).

So, in summary, I would imagine if some famous mathematician were to edit Wikipedia (and somehow I can imagine this extremely well even with a lack of imagination...) I would expect little problems. The math portion of Wikipedia functions quite differently than some other parts though. So I would agree there is a kind of expert problem. But I don't know how much of a problem it is to us. And let's not disparate the exotic sphere article too much, eh? It's not bad; it's informative, gives some good references. Certainly one can find a fairly elementary introduction by Milnor (in one of those MAA lecture series from the 70s) that is wonderful, but that's a very high standard to try and match.

In your hypothetical example, I imagine some people would read Milnor's article and it would get promoted to A-class :-). --C S (Talk) 07:16, 16 April 2007 (UTC)

I was certainly thrilled by what I read above concerning Scholarpedia, but before making your far-reaching judgements about its advantages and disadvantages viz. Wikipedia, take a look at the product. It touts itself as the new, wonderful model,

The approach of Scholarpedia does not compete with, but rather complements that of Wikipedia: instead of covering a broad range of topics, Scholarpedia covers a few narrow fields, but does that exhaustively.

Well, the first 3 links in the Differential Equations part of (supposedly, exhaustive) Encyclopedia of Dynamical Systems are Ordinary Differential Equations, Boundary Value Problems and Initial Value Problems. The first is worse than a stub: it's an announcement of the authorship; the second is a bit better, having a potential author and potential table of contents (with typos); the third (finally) is an article, but it jumps straight off into numerical solutions, with no explanation or motivation. I don't want to imply that the authors or curators lack qualifications, but let's put it this way: there is no Milnor (or anyone of comparable stature) among them. For the time being, I'd regard the site as a half-baked imatation of Wikipedia, with ambition, but uncertain future.

I have to differ with you about the authors. I have some history in nonlinear systems, and I was blown away by the calibre of people they have signed up - these really are the first team, people who defined and interpreted and are leading the subject. And Scholarpedia haven't signed up just a few: they've signed up dozens and dozens and dozens of them, and matched them to the most appropriate topics.

Kicking SP because most of the articles are only stubs seems premature: most of the topics in dynamical systems appear only to have been commissioned last month, or to be still going through the commissioning process. But most of the authors who have been commissioned are aiming to deliver in the next few weeks. If you look again in June/July it may be quite a transformation. (In contrast, how may WP articles now stubs will reach Good Article status in that time ?)

Where I think you might have more of a point is perspective. WP can't call on this calibre (or quantity) of talent, would take years to evolve to even mark out with stubs a survey this detailed, constantly faces articles losing their shape as more details are added that don't quite fit the original plan, and frankly, well, it's a rare article in a technical subject here that couldn't be substantially improved. But what WP does have, like a sandstorm smoothing a stone, is continual pressure to make things more accessible, and to make different articles fit together better, and to make articles appropriate for the pages linking into them. That matching of individual articles to a multiplicity of entry perspectives, and making them play together at a category-wide level, is what I would currently see as the most significant weakness in SP (version 0.1), and its authored approach. Lots and lots of old-fashioned editorial smoothing required - casting and re-casting of leads and intros to give more perspective and accessibility. Jheald 12:28, 16 April 2007 (UTC).

The larger point that was touched upon by User:Jitse Niesen is more interesting: why would the best of the experts write something for a web encyclopedia? I think that this question is incorrectly posed: given the spread of electronic publishing, TeX, arXiv and all that, it's remarkable how little of this is occurring so far! Now, I don't believe for a second that a world expert in a certain field needs any of this "peer review" hullabaloo to somehow validate their survey papers. In fact, it seems that there is a certain aura of purity about "peer reviewed publications" in public sentiment outside of academia, bordering on worship. Very few serious mathematicians rely on peer review to justify their work (there are some notable exceptions). Contributing surveys by invitation, on the other hand, has a long and distinguished tradition. I have little doubt that it can be extremely successfully transferred into electronic medium. If Wikipedia (or mathematics project) wanted to toy with the idea, it's quite feasible to invite the very same people to make a contribution, and quite possibly, many will agree.

On the other hand, I think that User:KSmrq's comments are very relevant. In my short (about one month) time on English Wikipedia I've seen pretty much the whole spectrum of his bullet points, some of which unfolded (or were mentioned) in this very discussion page! By the way, note that he was talking about perceived problems with original research, lack of clarity, undocumented statements, and so on, and being an expert in the field by no means shields someone for those kinds of issues! If anything,

• a famous author may attract unwanted attention from cranks, vandals, and possibly, scientific foes;
• an article on a popular topic will get scrutiny from legions of people who demand it to be comprehensible to everyone ("if it's in the news, why don't I get it? I graduated from high school and consider myself brilliant"), and I can easily imagine how having a high profile author alone can produce this effect.

Arcfrk 09:01, 16 April 2007 (UTC)

Warts and all, Wikipedia fills a need. I would not want that point to be lost. But to respond to C S: suppose I were to invite Marcel Berger[32] to write on geometry, as he has done with great appeal in his books; the article history forebodes ill, and I think his time would be better spent elsewhere. --KSmrq^T 10:18, 16 April 2007 (UTC)

This has generated an interesting discussion! I tend to agree with C S that things are not so bad in the mathematical oasis of WP. Vandalism is not intensive enough to be a problem: just hit that undo button and it is gone. And I've noticed that for every anonymous IP user who blanks a page or adds something scatological, there will be another who fixes a typo while browsing.

As for credit and peer review, one of the reasons that I contribute anonymously is that I don't want credit for any of my contributions. Also, if I were to be a named or invited author in article, I would want to maintain control over the article. So I'm not sure the wikipedia model is compatible with soliciting surveys. I like the WP model, but I think you need to have the right attitude/character to enjoy contributing here as an expert. I was recently browsing through the talk page at Lorentz group and I can see why Chris Hillman left. You have to be very flexible to contribute to WP. It also helps to be not just civil, but to make an extra effort to be friendly with other editors, especially when you disagree with them.

One area where I think WP lets mathematics down is in its desire to be a "general encyclopedia" in the Encyclopaedia Brittanica model. However, WP is so much larger than EB that it is really a whole new thing: a union of specialized and general encyclopedias. The mathematics coverage here is already becoming comparable with the Springer Encyclopedia. Unfortunately the generalist model has resulted in policies and guidelines which are not relevant or appropriate for mathematics. The whole concept of a featured article is totally unsuited to most mathematics articles, and it is not surprising to me that the few FAs we have are mostly on elementary subjects or are biographies. Having recently witnessed an FAC, and the inline citation crowd adding {{fact}} tags to any sentence which is not utterly bland, I have no desire for any article to which I have contributed significantly to become a featured article.

Perhaps we need our to define our own standard for the ultimate article, the FMA perhaps? Geometry guy 11:26, 16 April 2007 (UTC)

In general I don't think wikipedia is the right place for most academics. However I do think that they can help in someways. I've had good experience with emailing various academics and other experts on a number of topics, mainly for clarification on specific points, they have all been happy to help. Perhaps this a model, with us as a buffer between the academics ans wikipedia, work works best. --Salix alba (talk) 12:49, 16 April 2007 (UTC)

One point that I think is particularly relevant to mathematics here. The aim is not so much to have 'great articles' but a great piece of hypertext. So that (for example by the end of this decade) it would not be an empty boast that cutting-edge research mathematics can be referred back to definitions by an unbroken chain of blue links. Deligne said the proof of the Ramanujan conjecture would write out as 1000 pages of graduate level mathematics. We have a new model for making that less scary. Charles Matthews 15:51, 16 April 2007 (UTC)

Absolutely. By a quirk of fate I ended up doing interdisciplinary research, and ofter need to study small parts of new fields in a hurry - and fan out to the basic concepts needed, but no wider than that. Wikipedia with its blue word links is priceless, warts and all. Scholarpedia has more classical survey articles. There is a place for both. All these wikis are social experiments, and only time will show which equilibrium each one will hit. One aspect that Wikipedia is missing - when a professional mathematician spends a significant time on something he/she needs to take credit for it. Time is not free and even if the CV is thick the yearly increments do count. I write it off to paying back, public service and education, Wikipedia will make one a better writer over time. But from my short time here, many of us seem to be in the stage of their careers where they should seriously consider spending more time on writing journal papers than on Wikipedia in order to get that tenure or promotion. [added] A credit taking mechanism like Scholarpedia has would help and may attract more expert contributors. Jmath666 01:18, 17 April 2007 (UTC)

What do you mean by a credit-taking mechanism? Scholarpedia offers you an option: although you need to use your real name to register and you need to log in to edit, you can nonetheless edit either anonymously (but while logged in) or with your name on your edits in the edit history. Michael Hardy 01:37, 17 April 2007 (UTC)

Something to show on the CV for the time and effort spent that the tenure committee would consider. I have seen more than one case when someone was giving time and effort to noble things but the papers were not there so the ax fell. Authorship is more important than edits of course. I do not need that personally, but my guess is many of the best contributors here might. That may be a factor in favor of a model like Scholarpedia. Time will show. Jmath666 01:56, 17 April 2007 (UTC)

I for one don't think any tenure committee is going to be impressed by time and effort spent on Wikipedia or Wikipedia-like systems. Giving some way to give people credit on their vitae for those efforts is just going to lead to the committee asking why they aren't spending more effort on research. I think, as Jmath666 wrote earlier, that effort spent on WP is not only valuable community service but also that it is valuable practice in writing readably. But I don't see any kind of credit system as much of a draw, and I worry that such a system would lead junior into spending more time than they should in WP and hurting their careers. The way it is now, there's a clearer picture of what you're getting: a chance to help others understand the world better, but not really a step on the career ladder. —David Eppstein 02:17, 17 April 2007 (UTC)

There is an item for "service to the community" on our merit forms but it will not save the day. Maybe the whole business how we collaborate and publish will evolve towards some form of wiki. I see a pressure here towards original research all the time. Maybe the right way to parcel credit and control is would be the ingredient to spark the revolution. My group is already using CVS for pretty much everything, and I might set up a wiki instead for the next bunch; then it is only a step from a private server to online publishing. Jmath666 02:45, 17 April 2007 (UTC)

Tenure committees have different priorities at different schools, and in different departments within schools. Some give little weight to proven excellence in teaching; some give little weight to books authored. If the focus is on research, only peer-reviewed research publications count for much, and even then volume may not matter as much as perceived significance. Some journals garner more respect than others, and astute faculty judge accordingly. Like being kind to children and pets, contributing to Wikipedia can be a good thing; but don't expect it to help win academic advancement. --KSmrq^T 04:32, 17 April 2007 (UTC)

This brings to mind the ideal of a gift economy which is frequently applied to open source projects and online communities. Both academia and wikipedia opperate (information) gift economies, reputation in each is largely measured by the amount of information produced. In academia this is measured by the CV in wikipedia its the list of articles i have contributed to on your user page and things like edit count. As seperate economies there is a poor rate of exchange between the two, academic credentials matter little to WP and edit counts matter little to academia.

I'm definitly with David on my motivation for editing WP in that my motivation is to help people understand mathematics and wikpedia (despight all its problems) to me seems the most effective way of acheiving this. --Salix alba (talk) 07:41, 17 April 2007 (UTC)

Mean information

The article Mean information has been nominated for deletion. Comment as you see fit. Anville 19:49, 15 April 2007 (UTC)

Variable Shape Geometry

I guess this does not qualify as encyclopedic content per WP:NOR. Comments? Oleg Alexandrov (talk) 22:22, 15 April 2007 (UTC)

I received the pamphlet I referenced not too long ago in school. The front cover said Variable Shape Geometry by Val Bess and that's all. I asked one math professor about it and he said that it (the geometry) is still being developed and the pamphlet is what the "creator" has 'discovered' so far. I really don't know if it was published or not but it seemed worthy enough for an article so I made one.Burnedthru 22:33, 15 April 2007 (UTC)

What makes it worthy? I'd like to know. There's not enough in the article for me to really understand what this geometry is about. It seems kind of strange to include something you found in a pamphlet here in Wikipedia before many other, more standard notions of geometry are covered. Rybu 22:57, 15 April 2007 (UTC)

Before what others? Burnedthru 23:00, 15 April 2007 (UTC)

If more information is required, I'd be happy to add some, it's just that I have no one to ask at this moment and am pretty busy. Burnedthru 23:04, 15 April 2007 (UTC)

Non-commutative geometry is a big branch of modern mathematics. Variable shape geometry on the other hand, I doubt many people have heard of. My point is, just because somebody produces a pamphlet and includes the word geometry in the title, does that mean it should be linked to the geometry Wikipedia page? I don't understand Wikipedia's mission well enough to answer the question. I don't think any reasonable encyclopedia would include variable shape geometry in a listing of geometries, since it's obscure. But maybe Wikipedia is happy to promote anything, regardless of how obscure it is. Take your article on variable shape geometry for example. Does isometry group make sense for this geometry, and if so, what is the isometry group of the geometry? That would help me understand what this geometry is about. As it is, the article tells me very little about anything, other than some guys name. Rybu 23:14, 15 April 2007 (UTC)

This should go straight to AfD. It is not a question of priority: deletion is clearly justified under WP:NOR and the article seems to me to be palpable nonsense. For a start, semicircles (oblate or otherwise) are not parabolas (and how are they defined anyway?). Then we have "Later on, triangles can be proven to be squares because of the Congruency Postulate, which is very complicated." The congruency postulate is, of course, not defined. The word "indiminent" does not exist, and one of the diagrams has a "parabola" drawn between lines which are not parallel, contrary to the unexplained hypothesis. Lets not waste any more time on this! Geometry guy 01:45, 16 April 2007 (UTC)

I agree. I nominated it for deletion, see Wikipedia:Articles for deletion/Variable-shape geometry. Oleg Alexandrov (talk) 01:56, 16 April 2007 (UTC)

Euler on infinite series

Someone has proposed that Euler on infinite series be transwikied to Wikiquote. I think instead the article should be expanded to be more than just a quote. Perhaps some of this pages public can contribute. Michael Hardy 23:58, 15 April 2007 (UTC)

Can't this be merged into Divergent series?  --Lambiam^Talk 06:50, 16 April 2007 (UTC)

Category:Complex systems

Category:Complex systems is on CfD [[33]]. --Salix alba (talk) 15:01, 16 April 2007 (UTC)

Since I nominated the category for deletion, the category has been cleaned up, and a solid justification has been given for its use. It no longer looks like a category to collect anything that is just "complex" and a "system" according to the casual reader, and I would certainly not attempt to delete this category if it remained this way. However, it would be good to avoid having people put things like Category:Role-playing game systems back into the category because "they are called systems, and they look complex" (which describes why some articles and subcategories were in this category before clean-up). What are people's thoughts on renaming this as Category:Complex systems studies so that the category stays focused on the field of complex systems and does not become a category for anything named a "system"? Dr. Submillimeter 15:16, 18 April 2007 (UTC)

This may be a way forward, although I think something like Category:Complex systems science or Category:Complex systems (science) would be better. Geometry guy 17:16, 18 April 2007 (UTC)

I think the name as it is is fine, it is what people in the area use and it is not ambiguous with any other meaning for the same phrase. If the problem is people not knowing the technical meaning of the phrase and guessing that things belong when they don't, wouldn't it suffice to add appropriate text to the category page? —David Eppstein 17:22, 18 April 2007 (UTC)

The approach that some people take to categorization is similar to jamming a square peg through a round hole. If the category name vaguely seems to describe an article, then some people will stuff that article in the category even if it is inappropriate. Explanatory text may limit the problem, but some people will ignore the text anyway. Renaming the category with a less ambiguous name is a more robust solution. Dr. Submillimeter 17:46, 18 April 2007 (UTC)

If it must be moved Category:Complex systems (science) sounds good to me, Complex systems studies does not work for me as no one uses that term. BTW the category seems only weekly linked in the mathematical should it be included in Category:Chaos theory or Category:Non-linear systems. --Salix alba (talk) 18:55, 18 April 2007 (UTC)

Warel?

Please consider this list of edits which hits all of WAREL's pet topics. I didn;t see any that looked harmful; but I can't tell where the ja: links are going. Would people keep an eye on this? Septentrionalis PMAnderson 23:20, 16 April 2007 (UTC)

Of the first three ja: links I saw, one was valid, one was a change to the literal translation of the English title, which was a redirect at ja:, and one was a translation that didn't seem to have an article at ja:. In other words, the links seem to be made without any reference to existence of Japanese articles. JPD (talk) 10:58, 17 April 2007 (UTC)

12988816 (number) is nominated for deletion

12988816 (number) is nominated for deletion. The AFD discussion is here. CMummert · talk 15:55, 17 April 2007 (UTC)

Arabic/Islamic mathematics

Nationalists are trying to move this article to a silly title again. —Ruud 23:24, 17 April 2007 (UTC)

The article used to have the name "Islamic mathematics" for most of its existence. This is a rather common name for the subject (I get 19300 Google hits for "Islamic mathematics" versus 16200 for "Arabic mathematics"), and hardly a silly title. You yourself moved History of mathematics in Islamic culture to Islamic mathematics on April 28, 2006.[34] Then, on March 10 you moved Islamic mathematics to Arabic mathematics.[35] Why? Was there any discussion on this, and was a consensus reached? When User:Jahangard moved it back, complaining that the move was unilateral[36], you immediately reverted this, as far as I see without discussion why "Islamic mathematics" is a worse title than "Arabic mathematics"[37]. Was that wise? It looks like your March 10 unilateral move triggered the proposal to rename the article from "Arabic Mathematics" to "Mathematics in Medieval Muslim World". On the talk page, the supporters of the (ill-advised) proposed renaming appear to favour "Islamic Mathematics" over that long-winded title. My suggestion to you is to undo your last move, and try to obtain consensus that "Islamic mathematics" is to be preferred over "Mathematics in Medieval Muslim World". If such consensus has been reached, emotions have come down, and you still think "Arabic mathematics" is the best title, open a discussion about it.  --Lambiam^Talk 06:49, 18 April 2007 (UTC)

I think both "Arabic mathematics" and "Islamic mathematics" are fine (I personally even prefer the term Islamic mathematics, my move last month was motivated by more pragmatic reasons and, given the lack of dedicated editors of this article, more a case of WP:BOLD than a "unilateral action".) The proposed move is to "Mathematics in Medieval Muslim World", however. —Ruud 08:21, 18 April 2007 (UTC)

I was probably too frustrated yesterday and should have approached this in a more calmly and with more tact. I would appreciatie it, if some looked at it with a fresh look. —Ruud 09:09, 18 April 2007 (UTC)

Question on Relation notation

I've always seen a relation shown as something like x~y on some set S. And that this relation is an "equivalence relation" iff it is reflexive, symmetric and transitive. So that for instance you could have x~y if x<y on the integer set Z. So this relation would not be an "equivalence relation" since x is not less than x so x~x is not true and so ~ is not reflexive. So ~ is a relation but not necessarily an "equivalence relation". But the article on the following articles seem contradictory to this saying that ~ alone denotes an equivalence relation:

• Equivalence relation: An equivalence relation between a and b is often denoted as "a ~ b" or "a ≡ b".

• Tilde#Mathematics: In mathematics, the tilde, sometimes pronounced "twiddle," is often used to denote an equivalence relation between two objects. Thus "x ~ y" means "x is equivalent to y". (Note that this is quite different from stating that x equals y.)

Is there something I am missing here?--Jersey Devil 01:23, 20 April 2007 (UTC)

It's fairly rare to use the tilde for a relation that's not an equivalence relation, but you won't go to jail for it. Not sure I really understand your question, though. --Trovatore 02:08, 20 April 2007 (UTC)

You may not go to jail for it, but the physical world is not what one ought truly be concerned with. Rather one's soul. There is a very special section of Hades reserved for those that use a tilde for a non-equivalence relation. And it's the section that is not filled with interesting people. --C S (Talk) 21:52, 21 April 2007 (UTC)

I agree, x~y almost always means an equivalence relation. But suppose a broad survey finds that one third of the uses are for relations not satisfying equivalence (a generous estimate); the two "often" statements quoted are no less correct. (Note the word is "often", not "always".) As a practical matter, we are unlikely to be confused by seeing a "~" used with uncertain meaning, because authors habitually tell us the meaning they intend. --KSmrq^T 03:44, 20 April 2007 (UTC)

When I've seen ~ used, there really is an idea of equivalence involved -- not just a generic relationship. Two states in a communicating class in a Markov chain are "equivalent"... or whenever you have equivalence classes, for example, in the field of fractions (which, even though 1/2 and 2/4 are fractions of different integers, they are equivalent). In your example, x<y, this also fails because of symmetry (that if x~y then y~x, that is, x<y and y<x, which is clearly not true). However, even though < is not an equivalence relation, the relation ≤ over the real line is. I don't see the contradiction in the examples you give. - grubber 03:19, 20 April 2007 (UTC)

No, "≤" is not an equivalence relation, since it also obviously fails symmetry. Paul August ☎ 03:57, 20 April 2007 (UTC)

Grr, of course. My bad :) - grubber 17:17, 20 April 2007 (UTC)

Don't worry we all have mental lapses - mine come more and more lately. The distinguishing property between "<" and "≤" that you were probably thinking of is antisymmetry, which "<" fails, but "≤" satisfies, thus making the latter, but not the former a partial order. In fact , of course, "≤" is the archetypical partial order, hence the symbol "≤" is often used to represent any partial order, much like "~" is used to represent any equivalence relation. So there is that connection as well. Paul August ☎ 15:39, 21 April 2007 (UTC)

The ~ may be very often used to express equivalence relations, as the article says, but this does not contradict the fact that it is sometimes used for any relation, equivalence or otherwise. The confusion is simply that mathematical notation varies in different places and contexts. Perhaps the Tilde article could be updated to reflect the more general use of the symbol, but apart from that I don't see any issue at all. JPD (talk) 11:24, 20 April 2007 (UTC)

Strange edit at Relativity of simultaneity

• "Recent research in the history of mathematics has shed light on the mathematical suppositions Einstein brought to the formulation of the relativity of simultaneity ..." etc. -- it doesn't look completely incoherent and gives sort of some sources, nevertheless I'm sceptical. Comments? --Pjacobi 18:39, 22 April 2007 (UTC)

Someone had made word-for-word the same edit in general relativity, which I promptly removed. Its applicability to GR was even more dubious than its presence in the relativity of simultaneity. Silly rabbit 14:48, 23 April 2007 (UTC)

I've now seen it at History of special relativity too -- that just didn't look right. So I'll take it out and direct further discussion to Talk:History of special relativity#Connection with set theory?. --Pjacobi 16:21, 23 April 2007 (UTC)

An invitation to categorize uncategorized math stubs

Hello. The categorization taskforce is trying to find WikiProjects interested in using the bot of Alai to identify mathematics stub articles which do not currently have a category (besides the stub category of course). If the project is interested, we could create something like Category:Uncategorized mathematics stubs which could then be categorized by people knowledgeable in the subject, thus reducing the risk of improper categorization. Please let us know on the taskforce's talk page if you're interested. Cheers, Pascal.Tesson 00:23, 23 April 2007 (UTC)

Category:Complex systems nominated for renaming

I have proposed renaming Category:Complex systems as Category:Complex systems (science). Here is my justification for the rename:

I previously nominated this for deletion on 13 April 2007, mainly because it was being used to categorize anything that could be described as "complex" and a "system" by the average Wikipedia user (such as "role-playing game systems"). This actually seemed to categorize things by name rather than categorize things that were related to each other. Following the nomination, several people familiar with the scientific field of complex systems explained that the field deserved a category and cleaned out the category. However, the category is still at risk for being used to list anything that could be described as "complex" and a "system", and it would be good to have the category focus speficially on the field of complex systems itself rather than gathering together everything that could be called a system (like the deleted Category:Systems, which was deleted following a 12 April 2007 discussion; see User:Jpbowen/Back up - Category Systems). After a discussion at Wikipedia Talk:WikiProject Mathematics, a couple of people suggested renaming this as Complex systems (science), which I now recommend as the new name for this category. Dr. Submillimeter 18:06, 19 April 2007 (UTC)

Although I don't have a strong view on the rename, I originally suggested Complex systems (science) as an alternative to Complex systems studies. A better suggestion has now been made: Complex systems theory. I think this choice avoids most of the drawbacks of the rename (it seems to me to be as harmless as the distinction between relativity and relativity theory), while retaining the benefits. Comments can be added here. Geometry guy 11:11, 25 April 2007 (UTC)

Karel de Leeuw

I came across this article on a mathematician while working on categories. (Don't ask how.) The article says little about why this person was notable, although I suspect that part of the reason why the person was notable was because he was a murder victim. I may nominate it for deletion, although first I have asked the article creator to improve the article.

Is anyone here familiar with de Leeuw's research? Was he notable in mathematics? From this standpoint of this person as a mathematician, should the article be kept, or should it be deleted? Dr. Submillimeter 20:59, 19 April 2007 (UTC)

Tenured mathematicians at Stanford (even back then) are very notable. I also spy a publication in the Annals and several in lesser (but still prestigious) journals. --C S (Talk) 21:39, 19 April 2007 (UTC)

I do not concur that "tenured mathematicians at Stanford ... are very notable." However, if C S is correct is correct as to publications, that should be adequate for notability. I'm just not sure. — Arthur Rubin | (talk) 21:55, 19 April 2007 (UTC)

Please note that WP mathematician notability guidelines appear to be far more strict than those in other areas. This is particularly the case for anyone who's made a name for themselves on the net, e.g. various luminaries in the Linux/open source world, or in the computer gaming industry. The list of accomplishments are often of the form "so-n-so wrote this-n-such piece of software", yet the software is not particularly deep, original or complex. Point-for-point, they'd be completely outclassed by thousands of utterly anonymous engineers. Or, to compare to academia, the accomplishments seem at best comparable to those of junior math professors at state universities, the kind of which get AfD'ed. Yet, internet fame seems to be a deciding factor. It seems to be all so very unfair... linas 00:05, 20 April 2007 (UTC)

Dr. Submillimeter is right: many more people are familiar with the story of his murder (linked in the article) than with his research. It was a very high profile case, in my opinion, deserving coverage in Wikipedia. Arcfrk 00:10, 20 April 2007 (UTC)

I think the murder does contribute to his notability (hard way to get it!) but he would deserve an article without it. --Trovatore 00:14, 20 April 2007 (UTC)

Questions of notability would be easier to address if the name were spelled properly: "Karel de Leeuw" should be "Karel deLeeuw", without the space. Then a web search would find this description of his life and contributions. --KSmrq^T 03:55, 20 April 2007 (UTC)

He seems to have published under both spellings, so I don't know how you're picking which is the "proper" one. --Trovatore 05:48, 20 April 2007 (UTC)

Two factors: number of search hits (unreliable), and Stanford department remembrance. The article should mention both spellings, and should definitely draw on the information I linked above. I don't care enough to move it, but my leaning is it should be moved. --KSmrq^T 05:57, 20 April 2007 (UTC)

Better than search hits is MathSciNet. Have you looked there? It was a long time ago, but when I looked there seemed to be more listings with the space than without. --Trovatore 06:00, 20 April 2007 (UTC)

By the way, does anyone know if he's any relation to Jan de Leeuw, who definitely should not have a redlink? --Trovatore 06:02, 20 April 2007 (UTC)

Could someone please expand the article to indicate how the person was notable? Dr. Submillimeter 11:12, 20 April 2007 (UTC)

Just to conclude this for the archives, deLeeuw is notable for two reasons: his research and his murder. I suspect that after a few decades the murder will evolve into urban legend, since it seems to express two emotions common to graduate students. He was well liked by most students, and his murderer was frustrated by 19 years of failure. As to his research, the article's list of selected publications occupies as much space as the text, which surely is enough. The biography is brief, but a Stanford faculty member whose advisor was Emil Artin at Princeton, who was a Fulbright Fellow at Cambridge, who spent time at IAS, and who was a coauthor with Walter Rudin — clearly this man had something to contribute. As for the spelling, both Stanford and the mathematics genealogy project omit the space, while his publications do not.

Violence and murder are too common a tragedy in the U.S., and the victims are too often the generous and gentle souls. Perhaps Moez Alimohamed deserves a page as well, especially as Penn established an award in his name. Sadly, he has only this major publication left to represent his contribution to mathematics. Contrast the worth of these two individuals with the 65 names on the list of Formula One drivers who never qualified for a race. From the pages of Spider-Man, who himself saw his beloved uncle murdered, "'Nuff said". --KSmrq^T 21:21, 25 April 2007 (UTC)

I was bold, and moved it to deLeeuw, which most of the sources seem to use. Does anybody mind? If so, let's do WP:RM. Septentrionalis PMAnderson 05:29, 26 April 2007 (UTC)

Systolic geometry -- legitimate topic or link spam?

Please check out Systolic geometry. I noticed it when Katzmik (talk · contribs) twice put a link to it into Hyperbolic geometry. Both times I removed the link after looking at the article and not seeing any relevance to hyperbolic geometry. Apparently, Katzmik is Mikhail G. Katz, author of a book linked to by the article. He did not create the article, but he has done most of the edits to it. Do you think that this is a legitimate topic or is it just link spam? JRSpriggs 07:54, 25 April 2007 (UTC)

i think there is no reason to assume it's spam. requesting for clarifications from Katzmik (talk · contribs) seems to be a sensible thing to do. there's a section Systolic geometry that hints at some kinda relationship with hyperbolic geometry. perhaps Katzmik (talk · contribs) would be willing to expand it. Mct mht 09:29, 25 April 2007 (UTC)

This is an entirely legitimate topic, as far as I can tell. It's probably worth drawing the author's attention to WP:NOR. I think the AMS monographs are peer reviewed, but it might be best if the book is only used as a secondary source for the article.

As for the relevance to hyperbolic geometry, for one thing, the length of the systole will be a hyperbolic invariant. Geometry guy 12:08, 25 April 2007 (UTC)

If the AMS is willing to publish something, it ought to count as a reliable source for Wikipedia. The article is actually pretty reasonable, and lists numerous sources (there are some minor OR issues that would come up in an FA review, but this is a common problem). I agree with R.e.b.'s comment below that when experts want to improve articles in areas they are familiar with, and they write quality articles like this one, there is no reason to discourage them. CMummert · talk 18:39, 25 April 2007 (UTC)

Systolic geometry is a legitimate topic, it is indeed related to hyperbolic geometry, and Katzmik (talk · contribs) is an expert on it, who should be thanked rather than insulted for his efforts. R.e.b. 16:42, 25 April 2007 (UTC)

We have assume good faith for a reason. This case illustrates why. Charles Matthews 16:50, 25 April 2007 (UTC)

It looks perfectly legitimate to me. The basic definition is stated in such a way that it should be instantly comprehensible to everyone (except non-mathematicians, maybe) and that's more than can be said for some math articles. This seems like a good reason why an author should not be forbidden to put in an external link to his own book. Michael Hardy 20:53, 25 April 2007 (UTC)

Capitalization question

I was reading ordered field and noticed that the "Archimedean property" was capitalized, whereas in my Lang Algebra book, it is not. So, I noticed:

• abelian group: abelian never capitalized
• Archimedean property: Archimedean always capitalized
• Euclidean domain: Euclidean capitalized
• Gaussian distribution: Gaussian capitalized

I had always learned that when the property is modified (like with -ian), that it loses its "properness" and should be written lowercase -- and I have never seen abelian capitalized. But, on the other hand, I have always seen Gaussian written capitalized. I would prefer to never capitalize such adjectives (but that could look very strange with Gauss, Hamiltonian, Hilbert space, etc) Any ideas or has this been discussed before? - grubber 16:02, 18 April 2007 (UTC)

Capitalization of proper names in mathematical terms is sort of inconsistent. You say, for example, that "Archimedean property" is always capitalized. Nonetheless, number theorists routinely refer to non-archimedean valuations (actually, that article uses both capitalizations). I've seen both "Gaussian" and "gaussian", and in rather old books, also "Abelian" rather than "abelian". I can't remember who in particular I heard this from, but it's said that a lower-cased name in this context is a sort of honor, that the term has become so standard that it's not a matter of professional courtesy anymore, but simply a fact of life that, e.g., commutative groups are "abelian". In light of this, it's not really something that Wikipedia should regulate, in my opinion. Ryan Reich 16:32, 18 April 2007 (UTC)

This is to confirm what Ryan Reich said. I have two old group theory books (Herstein, and Hall). The first author refers to abelian groups, and the second uses Abelian groups. I don't think there's a standard in the literature, so Wikipedia ought not impose one. Oh -- I'm pretty sure I've seen both "Gaussian noise" and "gaussian noise" in physics/electrical engineering contexts. DavidCBryant 16:44, 18 April 2007 (UTC)

I would disagree here. As far as I know, not capitalizing "abelian" far outweighs capitalizing, so there is a pretty widespread convention; as indicated by Ryan's comments and your example, some old books may use capitalization. In fact, as pointed out by Dave Rusin in a nice sci.math post[38] it is the only name in the MSC that is not capitalized; I took a quick look and certainly abelian is not capitalized except when beginning the name of a category.

I'm not sure about other terms. If indeed it is a matter of preference, then Wikipedia ought not to impose as David said, but it would be silly to take this ambivalence to the extent of overturning a nearly unanimous convention. --C S (Talk) 17:01, 18 April 2007 (UTC)

(edit conflict) Once upon a time I was told such a rule too. But it's a rule many people don't use! As for "archimedean", I've seen it both ways. "Hilbertian field" can be either way too. It's interesting that indeed Gaussian (even in other cases as in "Gaussian integers") and Euclidean (in "Euclidean domain") is always capitalized. The usual way to find out if something is capitalized is to put everything in lowercase, submit it to a journal, and see if someone busts a gasket. I was told an interesting philosophy behind this lowercasing: that putting a name in lowercase is bestowing even greater honor upon the person; unfortunately an editor did not see it that way. So it goes.

Interestingly enough, I found this entertaining blog post [39] which has a comment which led me to Abelian group, where the note on typography states, "Among mathematical adjectives derived from the proper name of a mathematician, the word "abelian" is rare in being expressed with a lowercase a, rather than A (cf. Riemannian). Contrary to what one might expect, naming a concept in this way is considered one of the highest honours in mathematics for the namesake." Huh, no citation needed tag? ^.^ --C S (Talk) 16:52, 18 April 2007 (UTC)

(edit conflict) I was once told that it is the great honor of Abel that his was one of the few non-capitalized math names turned adjective. This is discussed outside of WP, but I don't think it is in WP:MSM, but maybe should be. Smmurphy^(Talk) 16:56, 18 April 2007 (UTC)

I'm not suggesting that WP should be the body that determines the standard. However, it would be nice to have a standard that we use consistently in all mathematics articles on WP (and alternate usage notes where appropriate); for example, a few lines in Wikipedia:WikiProject Mathematics/Conventions to discuss which one is "preferred". I hope that it would not degenerate into a "British vs. American spelling"-esque debate, although you never know :) - grubber 17:04, 18 April 2007 (UTC)

I agree with Ryan Reich that this is not something that we should regulate. On the other hand, I would not like to see the use of unmodified proper names without capitals such as hilbert space. I quite like the convention to decapitalize words derived from proper names, but not the proper name itself (even when used in a noun phrase like Hilbert space). Hence: Hermite polynomial, hermitian form, Gauss map, gaussian distribution, Abel-Jacobi map, abelian group, Klein geometry, kleinian group. (This convention is systematically used in French.) Geometry guy 17:11, 18 April 2007 (UTC)

PS. More importantly, though, Abel-Jacobi map is still a redlink! Can someone write a stub, or find a suitable redirect?

I'm writing an article right now. If anyone else is interested, wait a bit until I'm finished to avoid a conflict and then join in. Ryan Reich 17:40, 18 April 2007 (UTC)

The following, found in the Style manual of the U.S. Government Printing Office,[40] corresponds to what I believe to be the general rule for English:

3.3. Derivatives of proper names used with a proper meaning are capitalized.

Roman (of Rome) • Johannean • Italian

3.4. Derivatives of proper names used with acquired independent common meaning, or no longer identified with such names, are set lowercased. Since this depends upon general and long-continued usage, a more definite and all-inclusive rule cannot be formulated in advance.

roman (type) • brussels sprouts • venetian blinds • macadam (crushed rock) • watt (electric unit) • plaster of paris • italicize • anglicize • pasteurize

As far as I know this is also the prevailing rule in the U.K. Unfortunately the application of the rule is not authot-independent. While I write "angora wool", "benzine" and "cardigan sweater" without thinking of Ankara, Benz or Cardigan, I can't see "abelian" or "Abelian" without thinking of Abel. But in any case, I think we should preferentially follow general rules as laid down in authoritative style guides (rather than the possibly haphazard choices made by authors of mathematical texts) unless there is a compelling reason not to do so. (And note that in view of the completely different rule for French, texts by semi-French authors like Lang are perhaps somewhat suspect.) --Lambiam^Talk 19:26, 18 April 2007 (UTC)

Is there an authoritative style guide in mathematics? I remember looking at some Oxford general science writing guides, but they were not exactly helpful in this regard. While it's true that authors could be inconsistent (even between different texts of the same author!), but usage and grammar are not frozen in time, either: for example, capitalization of nouns was a lot more common even 100 years ago. Thus it may be preferable to consult current literature, with all the attendant faults, to using outdated manuals. Also, the last comment about Lang is a bit perplexing: it's true that he had peculiar accent, yet I never heard any implications that his English had been influenced by French or any other language, certainly, not in the context of his prolific mathematical writing (only small Bourbaki part of which was done in French, as far as I know). Arcfrk 23:25, 18 April 2007 (UTC)

Surely the rules are not topic-dependent? If it is Archimedean point with a capital A in philosophy, then also Archimedean property in mathematics. If it is Hamiltonian economic program in economic history, then also Hamiltonian path in maths. Rather than consulting outdated manuals, what about contemporary manuals that are kept up-to-date? The GPO Style Manual referred to above is from 2000.  --Lambiam^Talk 03:07, 19 April 2007 (UTC)

The problem is that different contemporary style guides almost certainly disagree. My opinion is that the best we can do - and this is not sarcasm - is to make each article internally consistent, and not worry about global consistency. CMummert · talk 03:14, 19 April 2007 (UTC)

I dont think we'll have a universal solution, but for each word I think we should make it consistent throughout WP. - grubber 03:16, 19 April 2007 (UTC)

I must agree with Arcfrk below; any given word is subject- (and author-) dependent. For example, I believe Frank Harary uses hamiltonian, and the usage in graph theory is clearly divided. We represent the state of mathematics best by being inconsistent. Septentrionalis PMAnderson 15:09, 26 April 2007 (UTC)

My impression is exactly that the rules are both subject-dependent and time-dependent (different editions of the same book may use different conventions), and mathematical usage tends to diverge from more general science usage. Arcfrk 03:44, 19 April 2007 (UTC)

Replying to your question on style guides in mathematics: The only one I know is Nick Higham, Handbook of Mathematical Writing, SIAM, 1993. Not a style guide, but a good reference for the finer points of typography, is Donald Knuth, The TeXbook. I also use P.R. Halmos, "How to write mathematics", Enseignements Mathématiques, 16:123–152. Perhaps we should start a list at Wikipedia:Manual of Style (mathematics)? -- Jitse Niesen (talk) 14:23, 19 April 2007 (UTC)

Yes please! Paul August ☎ 14:50, 19 April 2007 (UTC)

AfD: Mathematical landscape

Mathematical landscape has been nominated for deletion. Comment as you see fit! Anville 15:34, 26 April 2007 (UTC)

Calculi versus algebras

What is the difference between caluculi (e.g. propositional calculus,predicate calculus,proof calculus, and the various comp-sci calculi) vs. algebras (Boolean, heyting, etc)?

I was hoping to maybe find something on wikipedia explaining the difference, but I couldn't find anything. Brentt 03:03, 26 April 2007 (UTC)

Well, there's an ambiguity here that's caused us lots of grief in the past. "Boolean algebra", taken as a mass noun, means pretty much the same as the propositional calculus. Our article on Boolean algebra in that sense is (supposed to be) at Boolean logic, though the criteria for including information in that article are not particularly clear.

On the other hand, a Boolean algebra, count noun, is a mathematical object. It's not a calculus at all; it's an algebraic structure, like a group or ring. Not sure if I've helped, but it's a start; maybe we can narrow down what your question means. --Trovatore 03:17, 26 April 2007 (UTC)

I have always associated the word "calculus" with a method to manipulate strings of symbols in a meaningful way. There are "transformation rules" that tell you how to convert one string into another string. Not every transformation may be suitable for every string - you have to follow some rules. This matches the way that Newtonian calculus, lambda calculus, proof calculi, propositional calculus, etc. work. An algebra, on the other hand, is a set with operations such that any two elements can have the operation applied to them. In some cases, you can make up a semantics for the calculus that show that when the strings represent elements of a certain type of algebra then the transformation rules preserve some algebraic properties. But this is a very loose connection. Is that your question? CMummert · talk 03:35, 26 April 2007 (UTC)

Yeah, actually your first three sentences here are pretty much what I was getting at. The mass-noun sense of "Boolean algebra" is really a calculus; the count-noun sense is an algebra. (We should perhaps reconsider making Boolean algebra a disambiguation page, because this keeps biting us from time to time.) --Trovatore 03:52, 26 April 2007 (UTC)

Isn't an operation sort of a inference rule though? Brentt 00:57, 27 April 2007 (UTC)

Not sure what you mean by that. Can you elaborate? Note that the objects on which you're performing the operation may not be things you can write down in a finite amount of space. --Trovatore 02:32, 28 April 2007 (UTC)

Most of elementary algebra (where "algebra" is the mass noun) consists of rules for meaning-preserving manipulations on formulas (strings of symbols). In that sense, the algebra rules are much like (for example) the rules of the differential calculus, and one might call it a calculus. The soundness of these rules corresponds to algebraic properties enjoyed by the mathematical structure (possibly an algebra) whose elements are denoted by the formulas. The mathematical structures (such as rings) and the calculi (such as high-school algebra) live in different universes. For a Platonist, the mathematical structure has an existence independent of human knowledge; it was discovered. A calculus, on the other hand, is a human construction that was invented.

To complicate things, strings of symbols are themselves also elements of carrier sets of various algebras (for example, regular languages form Kleene algebras), and so we can also "discover" and examine the algebraic structure of some calculi. Given the somewhat frayed ends of most interesting calculi, this is usually not a rewarding undertaking, but for the Risch algorithm it definitely was.  --Lambiam^Talk 04:15, 28 April 2007 (UTC)

FAC of Equipartition theorem?

Umm, hi,

This is surely off-topic here, but I'm hoping that people here would be kind enough to evaluate Equipartition theorem, which is a Featured Article candidate now. It's at the level of basic multivariable calculus, although there is a multidimensional integration by parts at one step of the derivation. Does the article read OK to you all? Any suggestions for improvements? Thanks ever so much for your time and trouble, Willow 21:58, 27 April 2007 (UTC)

Mathematics ratings and tables

It seems to be regarded as a positive thing to put {{maths rating}} templates on talk pages as a way of tracking progress in our task to provide a good range of high quality articles, with emphasis on the most important ones. However, I am confused by the current organization and would appreciate some links/clarification/discussion. The whole process seems to be intertwined with the separate but related selection of articles for the CD-ROM Wikipedia1.0, whose classification we use (modulo our additional B+ class).

At first this seems fine: I follow the "mathematics grading" link on a template to Wikipedia:WikiProject_Mathematics/Wikipedia_1.0 and find explanations of the grading, with helpful tables of how many articles there are in each class, analysed both by importance and field, automatically generated each day by a bot - great! When I follow links in this table to a particular class (A,B etc.), or importance level (low, mid etc.), I find myself on a category pages which automatically list the articles in the given category - also useful!

Finally I follow the link to geometry and topology and I see something which looks even more useful: a list of articles in my field, ordered first by decreasing importance and then by increasing quality (class), together with comments, presumably from the template on the talk page. Wow, this is the most useful page of all!

But then I notice that the page is incomplete (articles with ratings that I know are not there), and has an extra "Has template" column. The page appears not to be automated (indeed it is months out-of-date). Then I remember WP1.0 and guess this is some list of articles chosen to go on a CD-ROM. Is this right, or am I just confused? Wouldn't it be really useful to have pages like these which were updated automatically from templates on article pages? Wouldn't it be better to have an extra column "Selected for WP1.0" (which could be, and is usually, indicated on the article page)?

Forgive these mumblings if I have completely missed the point, but the current structure has left me very bewildered about what is going on. Geometry guy 21:01, 12 April 2007 (UTC)

These per-field pages are not related to WP 1.0; they are just for in-project use. They aren't (yet) automatically updated, mostly because I haven't gotten around to writing the code. There are no technical obstacles to doing the updates automatically except that the automatic versions would not include the "comments" that the current tables do. It would not be too hard to write the code to update them at the same time the main table is updated. CMummert · talk 22:29, 12 April 2007 (UTC)

This definitely seems a good thing to do when you get the time. We are now getting to the stage where the number of rated articles has reached the level where further sub divisions is necessary. --Salix alba (talk) 23:42, 12 April 2007 (UTC)

Many thanks for the clarifications. It would be great if these pages were automated (although the "algebra" one would be a bit long unless stub class or low importance articles were somehow omitted).

However, one of the most useful things about these pages is that comments are there. Now there is a "comment" field on the {{maths rating}} template. This does not separate the comment from the author, but that is not important. At least in principle, couldn't the "comments/updated/has template" columns be replaced by a single column with the "comment" field of the article template? I know it requires someone to do the work, but it would be very useful and might encourage editors to use the "comment" field more often, and keep it up-to-date. Geometry guy 09:44, 13 April 2007 (UTC)

The table is created by using a database query interface to get lists of articles with various properties and then cross-referencing those lists to generate the table. These queries doesn't put much strain on the database and are very fast. In order to get the comments, it would be necessary to download the actual source of the talk pages and parse out the comments, which is a much slower and technically more difficult operation. At least the first version of automatic update wouldn't do it. CMummert · talk 11:33, 13 April 2007 (UTC)

I see, that's a pity. Does that mean that if we moved to an automatic update regime we would lose the comments completely on the field pages, or would it be possible to write the code so that it checks the current field page for existing comments and writes them to the new page? (I guess that would be more work to do, though, because it involves parsing the field page.)

Would it be feasible to update comments from templates as a separate operation that happens less frequently? Weekly would surely be enough, or the bot could cycle through the list of fields to reduce the daily load (so each page would be updated every 11 days). Well, I know this is work, and work which I am not able to do, but I think it might add some energy to the project to have such a system for monitoring progress. I would at least be willing to go through (some of) the existing field pages and merge the existing comments into the templates on the article pages.

Also, I wonder if this is something that Snowolf and Snowbot would be able to do for us. Even a one-off update of the pages would be great. Geometry guy 15:54, 13 April 2007 (UTC)

There are two ways comments could be be done. It can be specified as an inline field in the template, its can also be done as a sub page. This has been done on Talk:Blaise Pascal, with Talk:Blaise Pascal/Comments as the sub page. If this structure is used then it becomes a trivial matter to transclude the appropriate comment page in the listings of articles, using {{Talk:Blaise Pascal/Comments}} etc.

It should not be too problematic to migrate articles to this latter fashion, a bot could do this. It would only need to run once so the server load would not be problematic. I've changed {{Maths rating}} to put articles with inline comments into Category:Mathematics articles with inline comments. That category could be checked periodically to complete the migration. --Salix alba (talk) 19:25, 13 April 2007 (UTC)

This is a clever work-around — nice one Salix alba! I've changed {{Maths rating}} to put articles with a comments page into Category:Mathematics articles with comments page. There are not so many of them yet, so I was able to go through them by hand, fixing them if necessary so that they are not also in Category:Mathematics articles with inline comments. It would be nice to have a third category with Category:Mathematics articles with no comments, but that required me to pluck up the courage to make a more substantial edit to the {{maths rating}} template, or for someone with more Template experience to do it before letting me the chance to mess it up ;) Geometry guy 15:50, 14 April 2007 (UTC)

I wasn't courageous enough so I just added a Category:Mathematics articles with no comments page. I also wasn't careful with the includeonly/noinclude issue so the template itself is an example. This is just a temporary fix to see where we are now. I will not be at all offended if someone reverts my edit! Geometry guy 20:08, 14 April 2007 (UTC)

I plucked up a bit more courage, and my ugly code appears to work, although it has the side effect of raising the "field" field slightly. I expect this is due to my lack of understanding of spaces and newlines in template code, and I hope an expert can fix it quickly (and improve my ugly nested code!): explanations on my talk page most welcome (and don't be afraid to be patronizing!). Meanwhile the temporary category Category:Mathematics articles with no comments page needs deleting (I don't think this needs to go through CFD since it contains no articles!). Geometry guy 21:23, 14 April 2007 (UTC)

Proof of concept

Salix Alba suggests migrating from inline comments to only using comment subpages. I have no objection to that. I don't know the historical circumstances that led to the current redundant system.

If the comments are all moved to subpages then there is no technical problem with making the field summary pages. I wrote some proof-of-concept code whose results are available at User:CMummert/Sandbox4. That page is entirely automatically generated. Please let me know what can be improved. CMummert · talk 15:06, 14 April 2007 (UTC)

This is fantastic! Thank you CMummert! The only suggestions I have are cosmetic.

• A fixed width column for the article name would mean the coloured class boxes would line up nicely :)
• I can see that splitting the page up into "importance" sections is a logical thing to do, but I wonder if a left-hand coloured "Importance" column would look better. This also has the advantage that when browsing half-way down a long list, the importance level is still clear.

I will check out some of the existing per-field pages as promised above and report back. Geometry guy 15:50, 14 April 2007 (UTC)

I added a color key for the importance and tried to fix the table width. CMummert · talk 16:42, 14 April 2007 (UTC)

I like it! Meanwhile I've made a first pass through the current G&T page, copying the comments to /Comments pages. Now the second pass, to eliminate any duplication. Geometry guy 18:07, 14 April 2007 (UTC)

Second pass now done... From my point of view the current G&T page could be replaced by the proof of concept. Geometry guy 19:39, 14 April 2007 (UTC)

The plan is for all the field pages to be generated this way, unless there are objections. The argument in favor is that the old pages are horribly out of date and unlikely to be kept in sync manually as the number of rated pages increases. I just used the geometry field as a proof of concept to illustrate what can be done manually. CMummert · talk 21:39, 14 April 2007 (UTC)

I am completely in favour of all field pages being generated this way! However, there may be useful information on the current field pages which is not duplicated in the articles (In the geometry and topology test case, most of the information was duplicated, but I was able to incorporate some additional information into the article talk page in some cases). I think, however, editors interested in other fields should be given the chance to do what I did with G&T for a few days before the new automated scheme is introduced. Do you agree? Geometry guy 22:26, 14 April 2007 (UTC)

The proof of concept looks fine and generating all field pages automatically is an excellent idea. Do I understand it correctly that the comments column in pages like Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Analysis will be overwritten and that we thus lose the entries currently there? If yes, then that worries me. Is that necessary? A few days seems a rather short period. Can't the comments there be transferred to the /comments subpages (e.g., Talk:Manifold/Comments)?

I read an essay some time ago which I can't find anymore. Its main point was that we spend to much time on classifying and rating articles, while we should just be writing and improving them. I don't want to tell others what to do and rating articles is certainly useful, but I do want to raise the issue for you to consider because the essay struck a chord with me. -- Jitse Niesen (talk) 11:37, 15 April 2007 (UTC)

Most of these entries are essentially copies of comments in article talk maths rating templates. I believe a bot should be able to move these to /Comments pages: Salix Alba has created a category to facilitate this process. For the remaining entries, I don't believe moving them to /Comments is easy to automate, so I'm doing it by hand: I've done the work on the Analysis and Geometry and Topology fields so far. (Maybe User:CMummert would be willing to run the code on the Analysis field in another sandbox so we can see where we are so far.) Putting these comments on article talk pages is a useful thing to do anyway, I believe.

I agree entirely with your second point: classifications and comments are a means to an end - improving the quality and coverage of the artices - not an end in themselves: they should make it easy to identify where there is work to be done and what improvements are needed. To this end, they should be easy to update, easy to refer to, and easy to maintain. The present situation, with comments on an article placed by hand in two separate places, wastes editors' time that could be spent writing articles. CMummert's code would solve this. It also contains several other improvements: for instance, both article page and talk page are linked, and there are links to add comments to articles without them. Geometry guy 16:55, 15 April 2007 (UTC)

A proof-of-concept for analysis is at User:CMummert/Sandbox5. CMummert · talk 18:06, 15 April 2007 (UTC)

Thanks! Geometry guy 18:23, 15 April 2007 (UTC)

This is wonderful :-) I've always wanted the rating summary pages to be automatically updated and sorted. The most important thing is that they allow editors to prioritise their efforts (either on important or low-quality articles, accordingy to taste). Migrating the comments to the subpage is a sensible thing. (To be honest, the only reason why I used the "comment" parameter was laziness on my part - it was quicker than creating a subpage, esp. when rating lots of articles). (What would be really nice would be an AWB extension which allows one to rate/categorise an article and post a comment in one click.) So, I think the concept is definately proven. :-) Tompw (talk) 00:28, 17 April 2007 (UTC)

I agree, the concept is certainly proven to me, and there appears to be no disagreement on this now, so I suggest we implement it. I'll start a new subsection below in case further discussion is needed. Geometry guy 12:15, 19 April 2007 (UTC)

I'm planning to work on it this evening. CMummert · talk 13:08, 19 April 2007 (UTC)

Great! I've made a couple of suggestions below. I'll be glad to help out, anyway. Geometry guy 13:44, 19 April 2007 (UTC)

Progress on checking comments on field pages

I believe that all comments on the current Geometry and Topology page are now covered by /Comments pages. If someone wants to check what I have done, that would be very welcome, but from my point of view the current G&T page could be replaced by the proof of concept. Geometry guy 19:39, 14 April 2007 (UTC)

Note that not all comments at Analysis can be found in this proof-of-concept. This is because (I hope) they already exist in article talk page templates, and I've not migrated them to /Comments. As mentioned above, I really hope a bot will be able to do this. Geometry guy 18:23, 15 April 2007 (UTC)

I've now been through Algebra. This was relatively easy, as most of the comments are by Tompw (who almost always makes consistent comments on article and field pages). Geometry guy 19:34, 15 April 2007 (UTC)

I've now also checked Mathematical physics, which was relatively easy for the same reason. Geometry guy 20:21, 15 April 2007 (UTC)

I think we should not include the Mathematicians field in this process until an interested editor comments, as the format there is rather different (mathematicians are organized by year). Anyway, this means the checking is half-done, but I won't be able to do much more for the rest of the week. Geometry guy 22:17, 15 April 2007 (UTC)

In addition to the Mathematicians field, I also notice that there is a Theorems and Conjectures field. In the long term it would be nice to automate both of these, by adding e.g. a "mathematician=year" tag and a "theorem=Y" tag (cf. "vital=Y") to the template. Geometry guy 19:44, 16 April 2007 (UTC)

I've now checked the Basics field page. After automation, I think it makes sense to split Applied into Applied Mathematics and Probability and Statistics. These are, after all, completely different fields. It would also be convenient, I think, to split General into General Mathematics and History. The split pages could be given different names to save checking them for now. Geometry guy 19:44, 16 April 2007 (UTC)

I've now also checked Number theory, Discrete mathematics and Foundations. Subject to the above comments, this completes the checking process. Geometry guy 22:24, 16 April 2007 (UTC)

Thanks for migrating all those comments.

Probability/Statistics is already split from Applied Math in the rating template, it just doesn't have a ratings page like the others. I can easily add the ratings page. Similarly, General and History have different template parameters already.

So the only page that I think needs to be left alone is the mathematicians page. I think the best thing would be to move the old pages to subpages of their respective talk pages, so that they are still available online, and then delete them after a month or so if they are no longer needed.

Does anyone else have any thoughts about this? CMummert · talk 22:55, 16 April 2007 (UTC)

This is a good idea. I would also suggest moving the current "Applied mathematics" page to a (probably temporary) location ("Applied" or "Applied and statistics"). Similarly, the current "General" page could be moved to "General and history". The "Mathematicians" and "Theorems and Corollaries" need further discussion. Geometry guy 23:23, 16 April 2007 (UTC)

I'm sure there was a reason why I put Probability and Statistics on the same page as Applied, but I can't remember it... I think the history category was added as an option after the general page got created. Anyway, seperate rating pages for P&S and history are a good thing. I'll sort it out properly tommorrow morning (it's late, and I'll make silly errors if I do it now) Tompw (talk) 00:31, 17 April 2007 (UTC)

In response to "the best thing would be to move the old pages to subpages of their respective talk pages, so that they are still available online, and then delete them after a month or so if they are no longer needed": Perhaps it's better to have the bot overwrite the pages (I know I'm contradicting my earlier comment). The old versions are forever accessible on the talk page. You can add a link on the talk page to the old revision just to be sure. I don't see much point in moving the old pages to subpages, and very little point deleting them after a month. -- Jitse Niesen (talk) 01:54, 17 April 2007 (UTC)

I went through "General" and "Applied". In all cases but one, the comments were already included in the comment field of the maths rating template, so I didn't do anything. In the remaining case (Theorem, if I remember correctly), I migrated the comments.

So, now somebody has to move the comments from the template to the /Comments subpage. I could write a bot to do that, but I doubt I'll have time to do that soon. One thing I thought of: what happens for pages which fall in several WikiProjects? Should we instead make a /MathsComments subpage? Or should we assume that the comments are shared by all projects? The latter option has my preference (simpler is better), but there might be situations in which that doesn't work well.

Geometry guy, I deleted Category:Mathematics articles with no comments page. For future reference, the easiest way to get a page deleted is to put {{db-author}} on the page. -- Jitse Niesen (talk) 13:48, 17 April 2007 (UTC)

Thanks Jitse! I agree simpler is better. During my edits, the only places I noticed potential conflict with other WikiProjects were two or three articles such as Quantum mechanics which are joint with the Physics project. Even so, I think it is better (as well as simpler) to share comments between projects.

As for the migration of comments to /Comments, there are only about 130 pages to go, and there is no rush, so if we all move a comment from time to time (and I've done quite a few already), it will get done even without the help of a bot. See the categories created above for further information. Geometry guy 19:25, 17 April 2007 (UTC)

Implementation and theorems

There appears to be general agreement that the automatic of per-field ratings pages is a good thing for all fields except "Mathematicians" and "Theorems and Conjectures" (which is not really a field), and that "Probability and statistics" should have its own page, separate from "Applied mathematics". I therefore suggest we begin to implement it. I have a few other ideas as well. Here is a possible list of actions to strike out when done!

1. Move Geometry and Topology to Geometry and topology.
2. Similarly move Theorems and Conjectures to Theorems and conjectures.
3. Choose a consistent title for the field Foundations and mathematical logic aka "Foundations and set theory". Suggestion: Foundations, logic, and set theory. Move the old page to the new name. Fix Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Table accordingly.
4. Create new page Probability and statistics.
5. Replace existing field pages by pages automatically generated by CMummert's code:

   Algebra

   Analysis

   Applied mathematics

   Basics

   Discrete mathematics

   Foundations, logic, and set theory — VeblenBot needs to be told the new field name

   Geometry and topology

   General

   Mathematical physics

   Number theory

   Probability and statistics

6. Write code and run a bot to migrate current inline comments to /Comments page.

I wonder also if it would be useful to add a "theorem" tag the {{maths rating}} template to place articles into a category Category:Mathematics articles about theorems or conjectures (I'm happy to do this and tag the relevant articles). Could this then be used to automatically generate Theorems and conjectures? Geometry guy 13:35, 19 April 2007 (UTC)

I hope you don't mind that I numbered the bullets for easier reference.

Re bullet 3, I disagree - mathematical logic includes more than just set theory.

Re bullet 6, if these have all been done by hand then it is only necessary to remove the inline comment option from the math rating template. I don't think a bot is needed.

Re tagging the articles as theorems, this is already done via Category:Mathematical theorems. It would not be hard to cross reference the contents of that cateogry with the list of rated articles to find the intersection. CMummert · talk 13:53, 19 April 2007 (UTC)

Thanks for adding numbers.

Re 3, you cannot disagree with me :) as I did not express an opinion! I don't mind what the field is called, as long as the same name is used in the title of the page, in links to the page, and in {{WP MATH 1.0}}. However, if I were forced to express an opinion, I would say that, at least to a non-specialist, neither of (mathematical) logic and set theory is a subset of the other, so a more inclusive title would be be Foundations, logic and set theory. I think the word mathematical is unneeded, just as it is unneeded in (mathematical) analysis, because this is a WikiProject Mathematics category, and "mathematical" is understood.

Re 6, alas it has not been done by hand: there are still 131 articles with inline comments. Furthermore, editors continue to add comments using the comment method. Geometry guy 19:19, 19 April 2007 (UTC)

Could you tell again what exactly is to be done with these 131 articles? I would volunteer to handle some of these, if help is needed. Jakob.scholbach 19:37, 19 April 2007 (UTC)

Here is the process. Take an article talk page from Category:Mathematics articles with inline comments (for example, Talk:Abacus) . Remove the comment from the maths rating template and put it in the Comments subpage (for example, Talk:Abacus/Comments). If you can do a few of them, it would certainly help. CMummert · talk 20:49, 19 April 2007 (UTC)

Wikipedia:AutoWikiBrowser can make this process a lot easier. I've created a page at User:Salix alba/Sandbox which lists each page in the category followed by its comments page. You can make a list in AWB with it. Turn off all auto edit functions and make sure skip empty pages is off. The step through the list, cut the comment from the maths rating tag and save, go to the next page paste in the text and save. I manage to do about 30 pages in half an hour with this method. --Salix alba (talk) 23:00, 19 April 2007 (UTC)

The comments appear to be dealt with; check again in an hour or two to make sure the category doesn't repopulate. I edited the template to show an error when inline comments are left. The next thing to do is to make changes 1 through 3 and then wait a while for the job queue to update the articles. CMummert · talk 00:02, 20 April 2007 (UTC)

Very good! Clearly, I should learn to use AWB! Geometry guy 10:28, 20 April 2007 (UTC)

I have now checked that all comments on Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Theorems and conjectures are reflected in the article Comments pages. I've asked the marvellous VeblenBot if it can generate this page for us using Category:Mathematical theorems and Category:Conjectures. Geometry guy 11:16, 26 April 2007 (UTC)

History and mathematicians

I am no longer convinced that a separate Wikipedia:WikiProject Mathematics/Wikipedia 1.0/History page is helpful. At the moment it only contains two articles, and only one is really about history. There is already a WikiProject on the History of Science which rates articles, there is already the Mathematicians field, and I think it is more helpful to place articles like History of manifolds and varieties in the relevant mathematical field ("Geometry and topology" in this case).

One possibility would be to treat these as suggested above for "Theorems and conjecture" using a "history" tag to generate a category called Category:Articles about the development of mathematical concepts or something similar. Comments? Geometry guy 13:41, 19 April 2007 (UTC)

I've now added an experimental "historical" tag to the {{maths rating}} template to put articles in a Category:History of subject mathematics articles (not a great name, I admit). This could be used to autogenerate Wikipedia:WikiProject Mathematics/Wikipedia 1.0/History, while at the same time allowing historical articles to belong to another field. Geometry guy 10:32, 26 April 2007 (UTC)

This has now been used to autogenerate Wikipedia:WikiProject Mathematics/Wikipedia 1.0/History. I find the results very satisfactory! Many thanks again to CMummert. Geometry guy 01:05, 27 April 2007 (UTC)

Finally, does anyone have any ideas for the Mathematicians field? Sorting these by date is the hardest part. Would we be able to do it if every mathematician had a subpage containing their date of birth (or death)? Geometry guy 13:41, 19 April 2007 (UTC)

Although it's a couple of days late: do you mean that you want to be able to sort the mathematicians by date of birth/death? In that case, we actually have a very nice way to do that: persondata. It's special metadata for articles on people which includes (among other things) date of birth/death. Ideally all articles on people should have this, and it ought to be machine readable, so this should solve that issue. Of course, if that's not the issue you meant, then please ignore this. --Sopoforic 00:17, 22 April 2007 (UTC)

The difficulty with that is the bot doesn't download the articles or their talk pages, it only looks at category links and some 'what links here' links. The persondata info is machine readable, but only at the high cost of downloading the article. Putting the info into another subpage, as Geometry guy suggested, wouldn't help. If there is a way to do some crude sorting via categories, that could be made put into the bot. CMummert · talk 02:16, 22 April 2007 (UTC)

I see. It would, of course, be unnecessary to download the article for each update; once to retrieve the info initially and then perhaps monthly (or less often) thereafter would probably be sufficient. It should be possible to do something like this with categories, but that would be at the (very high) expense of manually inserting every article into the category. One ought to be able to put the articles into categories like this: [[Category:Dated mathematicians|1512]], where 1512 is the DOB of the mathematician. Presumably one would be able to extract this ordering from the category page, though not (apparently) the actual sort key used. This may be insufficient for the task at hand--I'm not totally sure what the goal is. --Sopoforic 02:42, 22 April 2007 (UTC)

The best way I see is to use the categories in sequence with Category:19th century mathematicians. This would at least allow sorting by century, so the sort order would be century, then importance, then quality. This is not technically difficult to implement, but the code to do it isn't written. CMummert · talk 02:58, 22 April 2007 (UTC)

Yes, that is what I meant, simply because the current page sorts the mathematicians that way. Sorting by century is one option, but there is the problem that many mathematicians straddle two centuries (e.g. Gaston Darboux and Elie Cartan). There are also Category:1917 deaths style categories, which I suppose in principle could be used, but this may be too complicated to be worth the trouble! Geometry guy 14:12, 22 April 2007 (UTC)

Mathematicians by year: a proposed way forward and some questions

There is now only the mathematicians page left to automate, so I have been looking at it again. There is in fact an obvious way to sort mathematicians by year: just make the table(s) "sortable". This can be automated using /Dates subpages giving the lifetime of the mathematician. Together with a couple of categories, such as Category:BCE mathematians and Category:First millenium mathematicians, sortable tables can easily be produced by transcluding these subpages. Such tables have the additional advantage that the tables can be sorted by importance or quality by clicking on the links provided by the sortable format.

It would be nice to be able to sort the table(s) also by name. One way to do this would be to introduce additional /SortName subpages, which give a sortable form of the mathematicians name (e.g. "Fermat, Pierre de" for Pierre de Fermat).

The creation of /Dates and /SortName subpages from the current page can probably be done using AWB (alas, I still don't have the expertise for this). However, there is another more subtle issue: at present the mathematicians page provides an additional "field" column, which lists the expertise and contributions of a mathematician, in addition to any comments on the quality of the article. This can partially be covered by the /Comments subpage. However, I think it might be useful to transclude another page containing the expertise and contribution information.

Many of these list entries describe the field(s) in which the mathematician contributed. This makes me wonder whether we should replace the "field = mathematicians" tag by a "mathematician = yes" tag, so the field is still free (for the primary field in which the mathematician contributed). One advantage of this would be the possibility to sort mathematicians by field. The mathematicians could then also be listed on the relevant field pages, although it is not obvious that this is necessarily a good thing, so please add comments! Geometry guy 19:47, 27 April 2007 (UTC)

Proof of concept for mathematicians

To show how this can be done, User:Geometry guy/Mathematicians Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Mathematicians now contains a sortable list of mathematicians with some dates. Most of the content of this page was automatically generated by VeblenBot with no change to the code. There are links for adding /Dates, /SortName, and /Contribs subpages to mathematician talk pages. At the moment, the sort order for the "class" and "importance" columns is not the natural one. Also, BCE and first millenium dates do not sort correctly. Feel free to make comments, changes, or add dates etc. Geometry guy 12:32, 28 April 2007 (UTC)

I've now added almost all the dates, and many sortable names to the table. I have also managed to make the class and importance columns sort naturally, as well as BCE and first millenium dates, although my solutions are not particularly elegant. Geometry guy 18:17, 29 April 2007 (UTC)

Apologies for not getting back sooner. The /Mathematicians table is nice, its certainly fun to be able to sort by dates class etc. I'm a little unsure about the /Dates, /SortName, and /Contribs sub pages, a perfusion of sub pages seems a bit excessive.

An alternatives is to use a database type structure to store the data. I've done a sort of database for the properties of polynomial at Template talk:Polyhedra DB, quite esoteric as its pre-parser function and could be much nice using a switch.

There are two ways this could be done, as one big page with the data for all mathematicians. Or with a sub-page per mathematician say /DB, this latter could be like

{{#switch:{{{key}}}|date=1970|sortName=Pascal, Blaise}}

this would save in creating too many extra pages and could be extensible.

One thing I've been doing on a separate wiki [41] is treating each wikipage as a object which has properties which are stored in a seperate table in the database. In the page, say in [[Pascal]] you can use {{#setProperty|date|1970}} to set a property, an extracted anywhere using {{#getProperty|Pascal|date}}. This is of course just wishful thinking as getting this implemented in wikipedia would be a task.

This might be a little too late to change things as I see you done a lot of good work creating the sub-pages, so we might as well stick to that style. --Salix alba (talk) 08:34, 30 April 2007 (UTC)

I agree that the profusion of subpages is not ideal and your ideas are interesting indeed. I think the data should be stored with each mathematician, but I am not wedded to the current (experimental) approach. The /DB subpage per mathematician is a nice idea, and it might not be too much work to migrate the data I have created to produce entries like

{{#switch:{{{key}}}|dates= Talk:Johannes Kepler/Dates |sortname= Talk:Johannes Kepler/SortName|contribs= Talk:Johannes Kepler/Contribs}}

(This above was generated by a template User:Geometry guy/MakeDB which might make the migration easier.) [Note added: I am now substituting for this template, so I can delete it from my user space.]

As I understand, I then just have to modify Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Mathematician row format template to replace transclusions like {{ {{{1}}}/Dates }} by {{ {{{1}}}/DB | key = dates }}, which is easy to do. Geometry guy 09:48, 30 April 2007 (UTC)

The mathematicians page has now been fully automated by CMummert and VeblenBot. However, in view of the above discussion, it may be subject to some change for a short period. Geometry guy 16:38, 30 April 2007 (UTC)

I have now copied the /SortName, /Dates and /Contribs subpages into /Data subpages of the form

{{#switch:{{{key}}}|dates = 1872 – 1984 |sortname=Guy, Geometry|contribs = Geometry, mostly}}

and modified the templates to use these /Data subpages in the Mathematicians table. The only disadvantage of this approach is that the /Data subpages appear to be empty. This could be fixed by adding instructions inside a "noinclude". I could do that, but it will take a while, even using AWB. Geometry guy 16:48, 3 May 2007 (UTC)

I've had a play about with Talk:René Descartes/Data and a template in my sandbox {{User:Salix alba/Sandbox}}:

• {{Talk:René Descartes/Data|key=dates}} gives: 1596 – 1650
• {{Talk:René Descartes/Data|key=sortname}} gives: Descartes, René
• {{Talk:René Descartes/Data|key=contribs}} gives: Geometry: analytic geometry
• {{Talk:René Descartes/Data}} gives: This subpage contains data about WikiProject Mathematics/Archive which is used by the Wikipedia:WikiProject Mathematics to produce tables of mathematicians. Edit this page to add or update the sortable name (sortname), date of birth or death (dates) and field (contribs) of WikiProject Mathematics/Archive.

---

• Name: Descartes, René
• Dates: 1596 – 1650
• Contribs: Geometry: analytic geometry

Basically whats happening is I've changed Talk:René Descartes/Data to be

{{User:Salix alba/Sandbox|{{{key}}} | dates= 1596 – 1650 | sortname= Descartes, René | contribs= [[Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Geometry and topology|Geometry]]: analytic geometry}}

with a template name instead of the switch. The key parameter to Descartes/Data is passed through to the second template. This is just a switch, but with a default argument which prints out the data in human readable form. if a parameter is given it just behaves as if the switch was there, no parameter, ie when viewing the /Data page you get the human readable form. --Salix alba (talk) 23:46, 3 May 2 007 (UTC)

Nice! Can you implement this? I know it is boring going through 147 articles with AWB, but I think it is worthwhile. Using a template as you suggest has the huge advantage (which I didn't appreciate when I created these /Data pages) that the format can be changed without having to change all the pages. For the same reason, it is probably worth being flexible about any "noinclude": I was going to transclude a template explaining how to edit these pages, but it might be possible to absorb this into your idea. Geometry guy 00:13, 4 May 2007 (UTC)

Geometry and topology is now live

Please look at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Geometry and topology, which is a test example of how to use the automated tables. Before implementing the other fields, I want to collect feedback on this one. It's worth looking at the source of that page to see how the implementation works. CMummert · talk 15:21, 20 April 2007 (UTC)

Perfect! I might slightly adjusts the column width. Links to the other field pages at the top could be helpful. --Salix alba (talk) 16:37, 20 April 2007 (UTC)

Still looking good! Maybe it is worth explaining in the lead how to Add or update Comments by following the handy links. Geometry guy 18:11, 20 April 2007 (UTC)

Looks good to me :-) Could we have {{WP MATH 1.0}} at the bottom? Tompw (talk) 18:30, 20 April 2007 (UTC)

It isn't obvious without looking at the page source code, but that page can be edited by anyone and the changes will not be lost. The tables themselves are included from another page, and changes to them will get overwritten. So it's possible to edit the lead section or add stuff to the bottom without having to ask me to edit the bot code. Tompw has suggested a way of formatting the tables so that the formatting will also be able to be tweaked from the wiki without changing the bot. CMummert · talk 20:06, 20 April 2007 (UTC)

(For the record, I suggested a template... it's at User:Tompw/sandbox12 currently, and is being trialed at User:CMummert/Sandbox5. Tompw (talk) 12:29, 21 April 2007 (UTC))

This looks really nice, but I have a small request. Having every comment field starting with 'Comments:' is a bit distracting, so is there any way we can do something like:

Consider re-nominating for Featured Article status. Tompw 12:25, 6 October 2006 (UTC) (edit comments)

I think the same link code could be used for articles with and without comments too. Cheers, darkliight^[πalk] 09:50, 21 April 2007 (UTC)

Like this? Tompw (talk) 12:29, 21 April 2007 (UTC)

Yeah I think thats much better. Is there any reason not to use the url that sends people straight to the edit page though? darkliight^[πalk] 13:42, 21 April 2007 (UTC)

Yes, there is... if you have an article with spaces in the name, you end up with an edit link like: coordinate system/Comments&action=edit (see source). Tompw (talk) 14:07, 21 April 2007 (UTC)

Ahh I see, no problem then, and thanks. darkliight^[πalk] 14:25, 21 April 2007 (UTC)

Can we find a work-around for this? Is there a method for replacing spaces by underscores? Geometry guy 22:13, 21 April 2007 (UTC)

Since anyone can edit the format I see no reason not to roll out the entire list. However, I have one more suggestion: these pages are probably all going to have essentially the same format, so why not have a single page or template describing this format, which can be included in each of the field pages. I've done this with Wikipedia:WikiProject Mathematics/Wikipedia 1.0/General so you can see what I mean. The format is defined at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Field page format. This makes it trivial to roll out the remaining pages. Geometry guy 13:55, 21 April 2007 (UTC)

That's a good idea. Tompw (talk) 14:07, 21 April 2007 (UTC)

I changed the bot to use a template to format the table rows and hacked with the template to make them get along. You can see the results at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/General. CMummert · talk 20:38, 21 April 2007 (UTC)

I bashed the template some more, and it all seems to be working OK :-). Are we ready to roll this out across the board?Tompw (talk) 21:12, 21 April 2007 (UTC)

The template I made was just a primitive first attempt: feel free to alter it radically! Anyway, this should be easy to do, and everything else seems to be well, so I will roll out the other fields. Geometry guy 22:13, 21 April 2007 (UTC)

I made the changes necessary because of the new name for the logic field, and updated the tables. That takes care of all the bullets above. There is still the remaining issue of a new "Theorems" field page, which could be automatically generated as well. That will take some time to implement. I want to say that the transition process went much more smoothly than I had anticipated because of Geometry guy, Salix Alba, Tompw, and others taking care of important parts of the work. CMummert · talk 23:59, 21 April 2007 (UTC)

That's the beauty of wikipedia! The response to my puzzled query has been fantastic, and with a great outcome. If I were in to barnstars and such things, I'd be awarding them to everyone involved, especially CMummert! Geometry guy 14:25, 22 April 2007 (UTC)

Category:Mathematicians by religion nominated for deletion

Category:Mathematicians by religion nominated for deletion before I could get to doing it. (Ask me about Slovenia!) Please go comment at Wikipedia:Categories for discussion/Log/2007 April 29. Dr. Submillimeter 22:49, 29 April 2007 (UTC)

Automated archiving

I have edited the source of this page to ask User:MiszaBot II to automatically archive it. If any errors occur, please remove the template from the very top of this page's source code. The cutoff is currently set for 7 days, and the bot appears to run at 6:35 and 18:35 UTC each day. CMummert · talk 13:33, 30 April 2007 (UTC)

Cultural comment

I added this comment to FOIL rule:

This mnemonic is not used by mathematicians and perhaps not known by most mathematicians, but is taught by secondary school teachers.

I took every math course my high school offered; the curriculum was better than at most high schools and I not only mastered calculus when I took the course but absorbed a lot of material beyond what was required in every course, and I NEVER heard of "FOIL" until as an undergraduate I was tutoring other undergraduates. It seems this mnemonic is completely universally known to everyone who hates algebra but is required to take an algebra course. Am I right to think that perhaps most mathematicians don't know it? Michael Hardy 17:39, 30 April 2007 (UTC)

Pardon me while I retch. An apt commentary is

• Stapel, Elizabeth. "'FOIL': A Special (and Misleading) Case." Purplemath. Available from http://www.purplemath.com/modules/polymult2.htm. Accessed 30 April 2007

Rote has its place, as in learning to add and multiply single digits. But in the case of this mnemonic, whoever is teaching the teachers should be taught better. --KSmrq^T 19:02, 30 April 2007 (UTC)

(edit conflict) Perhaps this is a generational thing (although I make no supposition about how old Michael Hardy is).  :) I grew up with this terminology as did most of my peers (currently or recently in grad school). It is often used as a verb, and in fact, its use has extended beyond even multipling two binomials together. Although technically incorrect, one might say, "Foil these terms together" when referring to multiplication of any polynomials, the idea being that you extend the idea of "FOIL" in a natural way to more terms. I'm not saying this should be mentioned in Wikipedia, but it is widely known among people I know. VectorPosse 19:06, 30 April 2007 (UTC)

I would definitely say it should be exposed in Wikipedia, along with other silly rotes that every recent high school graduate seems to know. I would even go as far as suggest a category: silly rotes (mathematics). As for generational thing, VectorPosse is probably right. It would be actually be interesting to pinpoint the origin of some of these widely known rules. On a side note, I pity the generation that had to grow up with things like that, as opposed to, let's say, Martin Gardner's amazing books and columns. Arcfrk 19:23, 30 April 2007 (UTC)

Teaching students this age is a challenge, and we should support — not ridicule — the teachers. Not all mnemonics are bad, and different students respond better to different means. Should we lampoon "SOH CAH TOA"? How about "xyzzy"? Pity the poor astronomy student who must remember star classifications. --KSmrq^T 19:55, 30 April 2007 (UTC)

Teaching in any age is a challenge, and one may choose whether to rise to the challenge, to supplement teaching with entertainment, or to dispose of the substance entirely. Far from ridiculing teachers, categorizing silly rotes is a first step to correcting the incalulable damage that they inflict on students of mathematics (yes, I said damage, and I mean it). If you want an amusing 'advanced' rhyme (which no one takes seriously, by the way), how about

Гомоморфный образ группы,

будь, во имя коммунизма,

изоморфен факторгруппе

по ядру гомоморфизма!

This is a poeticized form of the first isomorphism theorem widely known in Russia Arcfrk 20:16, 30 April 2007 (UTC)

Hmm; I think that second line will have to change for the English-speaking world. ;-) --KSmrq^T 20:59, 30 April 2007 (UTC)

I'm confused. What is this rule even about? Some weird kind of algebra with a non-commutative addition where one needs to remember the order in which the terms of the folded-out product comes? I fail to imagine a distributive law that could feel halfway natural and still dictate an internal order between the O and I terms. –Henning Makholm 20:25, 30 April 2007 (UTC)

Hypnotize yourself and regress back to a time in your life when words like "commutative" and "distributive" meant nothing to you. The order of the terms in FOIL is irrelevant; the point of the mnemonic is to help students remember the four terms of the result. Apparently their brains would explode if asked to understand and use the distributive law twice, especially since the pieces are not numbers but symbolic monomials. --KSmrq^T 20:54, 30 April 2007 (UTC)

I don't understand all the fuss.

The statement, "This mnemonic is not used by mathematicians and perhaps not known by most mathematicians, but is taught by secondary school teachers" seems a little strong. Why not just say "This mnemonic is often taught in secondary schools" and leave it at that? In the article it also says, "The FOIL mnemonic is commonly taught but is sometimes frowned upon because the method does not work, without modification, for higher order polynomials (the double distributive method, by contrast, is easily extended to the latter case). Foiling can thus be seen as an example of learning by rote memorization of rules rather than by understanding underlying concepts." But I always have to memorize base cases, and I can combine FOIL with recursion to expand the multiplication of sums of arbitrary terms.

I disliked the article on purplemath.com referenced above. It's primarily because the author adopts the tone of "this is the way I do it so this is correct and it is the way you should do it." I'd agree more with KSmq's second comment that "Not all mnemonics are bad, and different students respond better to different means." (I also have a strong distaste for the use of "simplify" to describe the process of expanding the multiplication. Yuck.)

IMHO, the "Factorization" section of the article should either be removed or modified. It's not at all clear how one FOILs in reverse.

My two cents, Lunch 20:37, 30 April 2007 (UTC)

Everything should be taken off the page that is not reliably sourced. I suspect this is US-oriented remedial material. Charles Matthews 21:12, 30 April 2007 (UTC)

On the talk page, Taxman commented in 2005 that "the phrase could certainly use some attribution to a reputable source, and I haven't been able to locate one." A web search for 'FOIL polynomial' brings up a plethora of supporting hits, so there is no question that this name is used for this topic. I suspect it is not just remedial, as educational standards for mathematics lack the Cold War motivation of Sputnik and the beneficial influence of an influx of educated immigrants fleeing Nazi purges. --KSmrq^T 21:30, 30 April 2007 (UTC)

(edit conflict, again.) About removing unsourced material, yes. About being US-oriented, I suppose so if someone from Europe says so. About remedial, no. It is, as I mentioned above, at least for people in my generation, common parlance. The points about rote learning are well-taken, but ultimately irrelevant to the article in question. In my calculus classes, I refer to it simply because "foiling" is easy to say and understood by everyone present. The article probably can be sourced, but I just want to point out that this term has widespread usage even apart from any pedagogical considerations. VectorPosse 21:33, 30 April 2007 (UTC)

My impression is that many textbooks discuss FOIL, but I don't have a stack of them handy. However, Steege & Bailey, Schaum's Outline of Intermediate Algebra, 1997, ISBN 978-0-07-060839-9, is searchable at Amazon.com; perhaps it will suffice for now. One can also find several discussions like this and this critique at "The Math Forum". --KSmrq^T 22:53, 30 April 2007 (UTC)

PS: Further discussion specific to FOIL should probably move to the article talk page. --KSmrq^T 22:55, 30 April 2007 (UTC)

Unital ring poll

There is an ongoing opinion poll at Talk:Ring (mathematics)#Poll on unit requirement as to whether or not the rings on Wikipedia should be defined to unital or not. Opinions welcome. -- Fropuff 04:22, 1 May 2007 (UTC)

May 2007

Dispersive PDE wiki

The dispersive partial differential equation wiki now has the gnu free documentation license listed as its copyright, which I think means that stuff from it can now be copied over into wikipedia (which seems to use the same license, though someone who knows about these things should confirm this). Maybe someone who knows about these thinks could make a template to say something like

This article incorporates material from ... from the dispersive PDE wiki, which is licensed under the GFDL

R.e.b. 21:18, 2 May 2007 (UTC)

Curves (disambiguation)

Theres been a dispute over whether Curves (disambiguation) and Curve (disambiguation) should be merged, which has now gone to RFC. So I though I'd invite the heavy mob over to Talk:Curves (disambiguation). --Salix alba (talk) 21:31, 2 May 2007 (UTC)

Georg Cantor

The tedious arguments at Georg Cantor over whether the great man was Jewish will simply not go away. Myself, I don't much care, except of course I want our information to be accurate, encyclopedic, and not confusing, even on fairly tangential points. If some editors here (especially, if such there be, ones with good knowledge about history) would help find a resolution, maybe we could get back to the serious business of crackpots who think they've refuted the diagonal argument.

My thoughts on the matter are summarized at talk:Georg Cantor#Edit wars over Jewishness or otherwise. --Trovatore 20:16, 29 April 2007 (UTC)

The problem here is:

• Cantor's grandfather, possibly also his grandmother, seem to have be born, or been by descent Jewish. His father and himself were deeply religious Lutherans; his mother Roman Catholic.
• Under these circumstances, he himself is not Jewish; "neither in an orthodox rabbinical sense, since his mother was Roman Catholic, nor in the sense of a practiced faith", as one authority says.
• Should the article have the Category:Jewish mathematician? The cat does allow for Jewishness by descent, but this is intended to cover cases like Einstein: unorthodox, unbelieving, or converted Jews.
• There must be a limit to how tenuous descent must be to count; otherwise we get like the helpful soul who catted Robert E. Lee as Scottish-American. (The Lees are thoroughly English, but claim descent from Robert the Bruce.)

This is a matter of definition, not of history, and I have no opinion on it. Septentrionalis PMAnderson 03:35, 3 May 2007 (UTC)

Unless he went out of his way to practice Judaism or to associate himself with Jews (which he did not as far as I know), then he should not be labeled as Jewish. Otherwise, we are adopting the pernicious idea that the Jews are a race (shades of Julius Streicher). JRSpriggs 07:04, 3 May 2007 (UTC)

Layout question

This is probably a stupid question, but how can I avoid the following layout problem (without taking the separated formula in the text body, of course):

• On a projective complex manifold X, cohomology groups of coherent sheaves F

H^*(X, F)

are finitely generated.

• next point

(I don't want the "are finitely generated" to start at the beginning of the line, but aligned with the text "On a proj..." and "next point"). Thanks Jakob.scholbach 18:48, 5 May 2007 (UTC)

I usually just put a colon at the beginning of the successive lines. This doesn't work perfectly but it's more aesthetic. I too have wondered if there's a real solution. Ryan Reich 18:55, 5 May 2007 (UTC)

Perhaps there is a better answer to this annoying behavior, but one dodge is to use HTML markup instead of wikiness, like so:

---

<ul><li>On a projective complex manifold ''X'', [[sheaf cohomology|cohomology]] groups of [[coherent sheaves]] ''F'',

<dl><dd>''H''^&lowast;(''X'', ''F''),</dd></dl>

are finitely generated.</li>

<li>next point</li>

</ul>

---

• On a projective complex manifold X, cohomology groups of coherent sheaves F,

  H^∗(X, F),

  are finitely generated.
• next point

---

And please, stop using quote-quote ('') as if it were TeX's math markup ($). If you want italic variables, italicize only the variables — not the parentheses nor the numerals nor anything else that gets in the way. (Fixed in my example.) Also, you may wish to consider using HTML &lowast; instead of an asterisk, as I have done. --KSmrq^T 19:35, 5 May 2007 (UTC)

"7 unsolved problems"?

This is sort of frivolous, but I didn't want to make any changes to such a contentious topic. Now that the Poincare conjecture is proven, and its proof is verified three ways from last August, shouldn't the "did you know..." factoid about the Millennium Prize problems read "there are 6 unsolved problems..."? Ryan Reich 23:42, 5 May 2007 (UTC)

Though to answer my own question, there is a pretty good argument that we should wait for the Clay Mathematics Institute to make it official. Ryan Reich 23:44, 5 May 2007 (UTC)

dashes in page titles

Recently an editor changes Poincaré–Birkhoff–Witt theorem to a redirect to Poincaré-Birkhoff-Witt theorem (the former uses en dashes, the latter hyphens) although it was quickly reverted. I know some of the math folk here have impressed upon others in the past that the en dashes are correct and should be used in the page title. WP:MOSDASH agrees that using the en dashes is correct (since these are different people's names) but states that for page titles simple hyphens should be used. A provision that it is ok to redirect to the dash title from the hyphen title has been struck out. After some investigation, it's clear that a discussion on the WP:MOSDASH talk page is what led to the previously mentioned edit; the discussion seems to have pinpointed a problem with saving pages with dash titles on computers using an older version of Internet Explorer. --C S (Talk) 06:54, 30 April 2007 (UTC)

What a silly thing for people to be worried about, exactly which dash belongs where. As far as I'm concerned there should only be one dash (the one on my keyboard) to avoid all the confusion. StuRat 16:43, 30 April 2007 (UTC)

Part of the point is that the different dashes have different meanings. If one writes about the Chan-Ho-StuRat theorem, one doesn't know whether it's a result by three people named Chan, Ho, and StuRat, two people named Chan and Ho-Sturat, etc., whereas if one writes about the Chan-Ho–StuRat theorem the distinction is more clear to those paying attention. So within the text of an article, using the right kind of dash can be important. As for titles of articles, I find the argument on MOSDASH unconvincing, especially because both names should be present with a redirect from one and the character appearing in the url will depend on which path one uses to reach the article, but whatever. —David Eppstein 16:55, 30 April 2007 (UTC)

Part of the problem with the guidelines is that the current practice is in flux. It appears to me that two years ago almost all titles were in ASCII, but now there is a definite trend for arbitrary Unicode characters in titles. So long as all useful redirects are in place, the actual title doesn't matter too much. CMummert · talk 17:06, 30 April 2007 (UTC)

The problem is that you can't save a page by saving a redirect! So, from the point of view of good typography and clarity, it is better to have Chan-Ho-StuRat theorem redirect to Chan-Ho–StuRat theorem, but from the point of view of everyone being able to save content, it is better to have Chan-Ho–StuRat theorem redirect to Chan-Ho-StuRat theorem. I agree the trend is towards unicode, so WP probably needs to introduce an error message like "You are using a badly designed operating system and/or browser. Please update your computer to use non-Microsoft products" for this situation. Incidently, Chan-Ho–StuRat theorem is still a redlink: is anyone going to make a stub? It could be a nice result ;) Geometry guy 17:19, 30 April 2007 (UTC)

WP:BEANS.  ;) --C S (Talk) 07:39, 7 May 2007 (UTC)

GA Review

The following articles are up for GA Review, feel free to comment.

• Exponentiation
• Homotopy groups of spheres
• Klee's measure problem
• Ordinal number
• Quadratic equation
• Sylvester's sequence
• Znám's problem

Hope to see you there. 74.116.113.241 01:18, 8 May 2007 (UTC)

Mathematics article assessment

Thanks to the efforts of several editors, the assessment of mathematics articles using the {{maths rating}} template is now considerably more useful and worthwhile than it was before. I thought it would therefore be helpful to summarize the current system and its benefits, and to encourage editors to add ratings to existing and new articles.

The maths rating is a template which can be placed (by anyone) on the talk page of any mathematical article to summarize its quality, importance and field, and suggest improvements that could be made.

What can article assessment do for you? The maths rating system is useful for directing our efforts towards improving the mathematics coverage of wikipedia. It also helps us to monitor the progress of this WikiProject. Although assessment is a means to an end, rather than an end in itself, it is a useful way to organize and monitor our efforts.

Recent improvements to the system mean that articles with maths ratings are now included automatically (with comments) in many useful tables. For instance, you can see the ratings for articles in your field (e.g. algebra), you can find stub class articles (listed by importance) to improve, or articles considered to be vital to the project rated by importance and quality. Rated articles about mathematicians are listed in a sortable table and there are also tables of theorems and conjectures and historical articles, sortable by field. All rated articles are listed in these tables (which are updated daily). They are also automatically included in a a hierarchy of categories. Every table or category has a navigation bar that links easily to any other.

What can you do for article assessment? There are many ways we can all improve this scheme to maximize its benefits.

• Add the {{maths rating}} template to the talk page of an article. For example, when creating a new stub, why not also start up the talk page with a maths rating?
• Add or update data in {{maths rating}} templates. There are may articles whose importance or quality is unassessed. Take a quick look at the assessment scheme and assess or reassess an article today!
• Add comments to an article with a maths rating. There is a whole category of mathematics articles which have no comments. A signed comment helps even just to date the maths rating, but even better, it can provide a summary of suggested improvements for the article that other editors can read.
• Add extra information about mathematicians. To make sortable tables, the dates, surnames, and primary fields of mathematicians are needed. It is too difficult to deduce these from page contents, so they are stored in a special format. Just click on the links in the mathematicians table to add or update these data.

Finally, you can contribute by making suggestions here or at Wikipedia:WikiProject Mathematics/Wikipedia 1.0 on how the scheme can be improved further. Many thanks. Geometry guy 01:39, 9 May 2007 (UTC)

The initial sentence in "probability distribution" is terrible!!

Here it is:

In probability theory, a probability distribution is a function of the probabilities of a mutually exclusive set of events.

That is idiotic nonsense. I had no idea this article was in such profoundly bad shape. I'm going to have to think about how to rephrase this. If someone beats me to it, I will be pleased. Michael Hardy 17:25, 7 May 2007 (UTC)

... OK, now I've changed it. I was shocked by what I read. Michael Hardy 17:33, 7 May 2007 (UTC)

Is it standard that the term "distribution" is restricted to measures over subsets of the real numbers, rather than the general case of measures over subsets of any possible space of outcomes (e.g., random curves)?  --Lambiam^Talk 18:19, 7 May 2007 (UTC)

The Encyclopaedia of Mathematics considers a probability distribution to be any probability measure of a probability space.[42]  --Lambiam^Talk 18:27, 7 May 2007 (UTC)

I'm not sure what's standard, but my old copy of Feller's book says that distribution functions are "non-decreasing functions which tend to zero as x → −∞ and to 1 as x → ∞." That seems to imply that a distribution function is defined in terms of a random variable that can only assume real values. On the other hand, I only have vol. 1 of An Introduction to Probability Theory and Its Applications. DavidCBryant 18:48, 8 May 2007 (UTC)

Well, of course obviously there are vector-valued random variables, and permutation-valued random variables, etc. etc. etc. I've now modified the first sentence accordingly. Michael Hardy 20:56, 8 May 2007 (UTC)

My impression was that "distribution" refers to something more complicated than a density function, but not as complicated as a measure. You use it with the Riemann-Stieltjes integral#Application to probability theory. JRSpriggs 06:22, 10 May 2007 (UTC)

Template:Numerical algorithms

The {{Numerical algorithms}} template appears to me as a rather indiscriminate collection of numerical algorithms, with a heavy bias towards root-finding algorithms. I don't know if it is necessary, and if it is, if grouping these together is any good. For example, it is of little use at Pseudorandom number generator and Fast Fourier transform. I would argue that it should be either thoroughly rewritten and posted on a different collection of articles, or otherwise deleted. Comments? Oleg Alexandrov (talk) 19:56, 12 May 2007 (UTC)

I agree that this navigation bar is useless (unbalanced, incomplete, and also inaccurate). That might, perhaps, be fixed, but in this case I don't understand what aim it could achieve that is not much better addressed by categories (for navigation) and a good overview at Numerical analysis.  --Lambiam^Talk 21:10, 12 May 2007 (UTC)

The obvious thing to do (and probably the least work) would be to move the template to "root-finding algorithms" and remove all the other stuff. Geometry guy 21:38, 12 May 2007 (UTC)

Having looked at it, my first instinct is to delete it as a useless eyesore. While deleting from each article, add a category as Lambiam suggests. --KSmrq^T 21:43, 12 May 2007 (UTC)

OK. Jitse, our numerical guy, agrees too (on his talk page). I removed it from articles and deleted it. Oleg Alexandrov (talk) 15:39, 13 May 2007 (UTC)

As yet to be added mathematics articles

In my quest to assess every mathematics article I came across several articles that were in the purview of this Wikiproject that had not been placed under its supervision. This troubled me and I would like to know what can be done to add these articles to our project efficiently. The articles I have found thus far are Mandelbrot set and Lorenz attractor but I am sure there are more out there.--Cronholm144 18:52, 12 May 2007 (UTC)

You mean, articles without the Project Math banner on their talk pages? Just do what you did to Mandelbrot set, add one there. Also, add a mathematical category (e.g. Category:Fractals) to the article itself if it should have one and doesn't. —David Eppstein 19:02, 12 May 2007 (UTC)

According to the table of assessed mathematics articles there are about 1000 assessed articles. On the other hand the list of mathematics articles contains about 15000 articles. Previous discussions have not supported the automatic tagging of these articles (see Wikipedia_talk:WikiProject_Mathematics/Archive_18#.7B.7BMaths_rating.7D.7D and Wikipedia_talk:WikiProject_Mathematics/Archive_24#Tagging_math_articles) and have suggested that assessing all these articles might not be a sensible goal. However, the current assessment coverage is rather haphazard, and I would encourage editors to add maths ratings to any articles which they consider to be important to the project. Geometry guy 21:08, 12 May 2007 (UTC)

I've started going through the A-Z of mathematics articles (there are 13216 of these, but there are also mathematicians and nonalphabetical articles). I thought it would be useful to add maths ratings with importance and field to some of these articles to make the coverage less patchy. This is mundane but straightforward to do using WP:AWB because the field and importance can usually be judged approximately from the title alone. Fortunately, I am being supported by other editors, especially Cronholm, who are keeping tabs on me and filling in quality gradings (I have also added quite a few quality gradings myself). My ratings are a very rough and ready assessment, but I think it is more useful to have someone's opinion rather than none at all. My motivation is that it will be easier to judge issues such as importance when articles can be compared in the many tables that have been created.

So far I have been through the letters A and B, which took about a day, so help would be much appreciated! I'm restricting myself to providing ratings for at most an additional 1/3 of the listed articles (there are certainly enough worthwhile articles to rate this many). Hence, if I don't run out of steam, the number of rated articles will increase from c. 1000 to c. 5000. I hope this is enough to provide a good cross-section of our coverage, but not too much to overwhelm the rating system (or other editors!).

I am making mistakes in this process: although I am trying to be careful, it is easy to add a rating to a redirect or a dab page, or rate an article which has already been rated. Please fix any mistakes you find. Furthermore, if in doubt I've tended to underrate an article's importance and/or quality, so please don't be offended if I have assessed your favourite topic as "low importance" or called your hard work "a stub". Uprate where appropriate! Even better, add to the article! Geometry guy 21:14, 13 May 2007 (UTC)

One third and one quarter

I nominated these for deletion at Wikipedia:Articles for deletion/One third, as not encyclopedic in my view. Comments on these articles are welcome there. Thanks. Oleg Alexandrov (talk) 22:00, 12 May 2007 (UTC)

Mythical number

This survived AfD, although it could use a rewrite. Michael Hardy also suggests a new title, since this is not a class of number, but an essay on bogus statistics. Can anyone think of a good one? Septentrionalis PMAnderson 23:05, 12 May 2007 (UTC)

Imaginary number? Seriously, I think that is how such made-up numbers that achieve mythical status are known. Plenty of Google hits with this meaning.  --Lambiam^Talk 00:03, 13 May 2007 (UTC)

Michael seems to be thinking of something more descriptive, like unsourced statistical claims; or apocryphical, anecdotal, numerical.... to which mythical number would redirect. Septentrionalis PMAnderson 18:38, 13 May 2007 (UTC)

Yes, the current title makes this a bit too much like a book ad. I'm not against citing the book, but centering the article around it is not a good idea. On the other hand, any alternative title should be in plain enough language not to be OR. Apocryphal statistics and anecdotal statistics both seem to capture the flavour of the article to me: the numerical aspect is reflected in the plain language meaning of the word "statistics". Geometry guy 19:09, 13 May 2007 (UTC)

Which book?  --Lambiam^Talk 20:26, 13 May 2007 (UTC)

Sorry, the cited reference reads a bit like a book title, but it seems to be an article. I still think the title revolves too much around one primary source. Geometry guy 20:34, 13 May 2007 (UTC)

Protect geometry?

I put the article Geometry on my watchlist about three weeks ago. In this time, there have been multiple acts of vandalism committed on that page, from blanking and replacing it with expletives to inserting childish non-sense that the contributor considers to be amusing. Almost without an exception, these edits were performed by anonymous users, and some anonymous users (at least one of them with a history of vandalism more extensive than many an editor's list of contributions) targeted the page repeatedly. It is easy enough to understand why is this happening: this is one of the most high profile mathematics articles. Precisely for that reason I think it should also be a model article, not alternate between the states of being an encyclopaedic article and the latest in the junkyard.

It's true that it does not take too much effort to revert an unwelcome edit. However, should we just shrug and carry on, apathetically reassured by technical convenience of reverts, or can we take a more pro-active approach? My assessment is that in this case, at least, the nuisance of the anonymous vandalism far outweighs the modest benefit of having occasional serious anonymous editor contribute. What do other people here think of protecting or semiprotecting Geometry, as has been done in the past with Mathematics and other popular articles? Arcfrk 03:08, 8 May 2007 (UTC)

Hey! Some of us like having geometry in the junkyard! (Not disagreeing with your point, just amused by your wording.) —David Eppstein 04:10, 8 May 2007 (UTC)

Geometry in a junkyard ("thrackles"?!) is not the same as throwing junk into "geometry". :-)

I, too, have watched the unending stream of petty vandalism, and would support semiprotection. (Full protection seems unnecessary.) --KSmrq^T 04:50, 8 May 2007 (UTC)

Somehow my previous comment disappeared: Yes, I think, semiprotection would be a good idea in this case. Jakob.scholbach 05:01, 8 May 2007 (UTC)

I agree. While we're at it, the incidence of vandalism edits at Randomness is also high (1.6 per day, compared to 1.1 per day for Geometry, measured over the last 100 edits), presumably because the perpetrators pick, predictably, a "random" target for their random actions.  --Lambiam^Talk 05:35, 8 May 2007 (UTC)

I applied for semi-protection of Randomness recently. It was denied (as most of my requests are) on the grounds that there was not enough vandalism to warrant action. Read that to mean that we waste less than two hours per day reverting it. By the way, KSmrq again wiped out another person's edit (Jakob.scholbach's) and did not fix it. JRSpriggs 11:49, 8 May 2007 (UTC)

The criterion is heavy and continued vandalism. It is continued, the question is what is heavy? Charles Matthews 12:15, 8 May 2007 (UTC)

The problem with semiprotecting articles is that it doesn't get rid of annoying vandals - it just moves them elsewhere. If only a few articles are protected, the vandals will just pick an unprotected one. If a large enough number of articles became semiprotected, it seems possible that the vandals would just start getting usernames, which are free anyway. On the other hand, semiprotection goes against the idea that "anyone can edit" and may discourage new productive editors from joining.

So the traditional standards for semiprotection are very high. Except in cases of libel or copyright violation, the traditional standards want the vandalism rate to be so high that it cannot be dealt with via watchlists and manual reverts.

I think that there is shifting opinion about semiprotecting articles. If you watch WP:RFPP you will see that some admins have lower standards, and the people requesting semiprotection have much lower standards, than what has been required. Maybe in a few months the standard could be lowered some.

And they keep promising that "any day now" the German wikipedia will start experimenting with stable versions, which may also reduce vandalism. CMummert · talk 13:48, 8 May 2007 (UTC)

There seems to be consensus among the editors that it is worth trying to semiprotect Geometry, but a caution from CMummert that it may contradict the current practices of Wikipedia's administrators. While I agree with him that protecting the page does not solve the problem of vandalism completely (e.g. the vandals that have been turned away can still cut their favourite four letter words on their desk in their classroom), I do not believe that this point is relevant for the question at hand. Of course, it all depends on how you interpret the purpose, but here is my statistical analysis of last 100 edits of Geometry, between 20:52 March 27 and 17:14 May 10:

• 2 bot additions of links
• 2 major edits (I expanded the article)
• 3 minor edits (corrections of a single word or sentence)
• 93 edits that are either acts of vandalism, addition of irrelevant information, or reverts.

Thus, over the last 100 edits the vandalism rate is 93%, while the major editing rate is 2%. To answer Charles Matthews's question, I believe that the situation can be accurately described as heavy vandalism. Now, it's true that there are fewer than fifteen attacks per day on that page, but does anyone seriously believe that unprotected status of that page contributes in any meaningful way to its development? If anything, I would conjecture that several well respected editors, while having the page on their watchlist (judging by the promptness of their reverts), choose not to contribute, given the present environment. Ksmrq indirectly confirmed it about a month ago on this very talk page. It is demoralizing to realize that the 'right for anyone to edit', which in this case translates into the opportunity for any dim-wit who has learned to swear, any pupil frustrated with his maths lessons, and anyone bored with encyclopaedic articles to vandalise the page, trumps the reasonable expectation of serious contributors to Wikipedia that their efforts to improve the content are supported in a meaningful way. Just to give you one example of how vandalism disrupts normal editing process, I stumbled across interesting pieces of text that had been a part of the text a while ago, but are no longer present. Given the vandalism rate, I do not have time to work with the page history to trace what has happened to those pieces of text.

Conclusion: if we adapt the pragmatic point of view that our goal is to improve the content of Wikipedia, then semiprotecting Geometry (while not solving the ills of the society as a whole) would be a valuable action towards accomplishing that goal. And conversely, leaving the article unprotected, as a punching bag for all sorts of vandals, sends the wrong message about Wikipedia's priorities. Arcfrk 08:07, 11 May 2007 (UTC)

I agree with you. Now if we could just get the people at Wikipedia:Requests for page protection to agree. JRSpriggs 10:51, 11 May 2007 (UTC)

Any admin can protect or semi-protect a page; this does not require action or agreement of some kind of people "at" the requests page.  --Lambiam^Talk 12:59, 11 May 2007 (UTC)

I think that Arcfrk's argument is very compelling, but I understand the arguments against protection as well, which are based on the Wikipedia Foundation policy that anyone can edit here. If this issue were limited to Geometry, I would semiprotect it right now. The main concern I have about protecting Geometry is: how many other articles would end up protected if the same standard was used on them? On my watchlist, I know Randomness would. CMummert · talk 13:25, 11 May 2007 (UTC)

I asked about this here this morning, and there are a couple of replies in favor of (at least temporary) semiprotection. I am quite willing to protect Geometry, but I want to know how many more pages are going to be requested before I start sliding down any slopes. CMummert · talk 23:57, 11 May 2007 (UTC)

I did mention Randomness.[43] But if all editors who have Geometry on their watchlists now add Randomness to it, I think we can manage for the next couple of weeks. :)  --Lambiam^Talk 09:45, 12 May 2007 (UTC)

I'd agree with semiprotecting this temporarily, say for a week. About the fact that this is a slippery slope, that's correct. Well, the wiki model is evolving, some limits to editing may turn out to be necessary, although of course articles should be semiprotected only when necessary and not for too long. Oleg Alexandrov (talk) 04:58, 12 May 2007 (UTC)

I have semiprotected Geometry for two weeks. C Mummert · talk 05:30, 12 May 2007 (UTC)

So, what's on your watchlist?

Perhaps I'm being naive, but it seems to me quite unwikipedian to go around protecting articles. Wouldn't a better way be to have some kind of shared watchlist for heavily vandalized articles? Is there already such a facility that I don't know about? If not, someone could just provide a list of problematic articles in their user namespace (or even in Wikipedia/Wikipedia_talk namespace). Others could add articles as the need arose. Silly rabbit 11:52, 12 May 2007 (UTC)

There's no shared watchlist. About which articles are vandalized, it is usually high profile ones, like mathematics itself, then the math portal and all its subpages, and then, well geometry. Oleg Alexandrov (talk) 15:25, 12 May 2007 (UTC)

The closest thing is the "Related changes" tool, on the left side of the screen. If you go to one of the field subpages of this table and then select "related changes" you can get a list of changes made to the pages there, like this [44]. It's not quite the same as a watchlist because multiple changes to the same article are shown. C Mummert · talk 15:37, 12 May 2007 (UTC)

I ask because I have noticed that some (perhaps) not-so-obvious pages seem to fall into the same category. For instance, mean seems to be a mid-level target for the odd vandal now and again. And, although it certainly scores lower on any quantitative assessment of vandalism than geometry, mathematics, etc., it's also a lesser concern to editors wary of the problem of vandalism in general. Personally, I'd be happy to put any article that seemed to be in modest trouble (such as mean) onto my own watchlist. Silly rabbit 16:05, 12 May 2007 (UTC)

A few more pages I've seen frequent vandalism on: Pythagorean theorem, Buoyancy, Fibonacci number. —David Eppstein 16:55, 12 May 2007 (UTC)

Algebra seems to be attacked as much as Geometry, although, amazingly, unlike the latter it undergoes productive development at the same time. Arcfrk 06:08, 13 May 2007 (UTC)

It would be trivial to create a "shared watchlist" of vulnerable pages: create a page as subpage of this WikiProject, listing links to those pages, and ask people to consult "Related Changes". Charles Matthews 14:02, 13 May 2007 (UTC)

More interesting would be a "shared patrol-list", which answers the question "has someone whom I trust reviewed the most recent changes?" That way, I can avoid reviewing something that you've already reviewed and let pass. linas 00:05, 15 May 2007 (UTC)

Wikipedia:Articles for deletion/Algebraic bracket

Could someone have a glance at Algebraic bracket and this AFD entry? Needs expert comment on accuracy / worthiness for keeping. Thanks. Tearlach 02:21, 14 May 2007 (UTC)

Nominate it for AfD. It has no context, and it's completely isolated on wikipedia. Such things are useful in deformation theory (see Gerstenhaber algebra), but if the need should arise, it's likely to be dealt with inline anyway. So, no harm done. Anyway, I objected to the term algebraic bracket ages ago. Silly rabbit 02:36, 14 May 2007 (UTC)

I'd prefer to keep this as a reminder that there are algebraic brackets, and this is one of them. We don't delete orphans on WP: we find them a family. I've known the term "algebraic bracket" since my early postdoctoral days, when I spent some time thinking about them with a few experts. I'd be happy to move this particular instance to a more specific title, though. In the long run, "algebraic bracket" itself might be a nice dab. Geometry guy 03:29, 14 May 2007 (UTC)

I am not at all sure it's a good title, but the concept is important, and the article seems to have plenty of references (in case you needed context). Definitely keep! Arcfrk 13:54, 14 May 2007 (UTC)

I closed the discussion after the nomination was withdrawn. The article was moved to Nijenhuis-Richardson bracket. -- Jitse Niesen (talk) 04:02, 15 May 2007 (UTC)

Most linked to math articles

I made a list of math articles which are most linked to from other math articles. The list is at User:Mathbot/Most linked math articles.

My goal was a metric for assessing the importance of math articles. I think the higher an article is on this list, the more important it probably is, and the more crucial is for it to be in good shape. This is imperfect of course, but is better than not having anything.

Also, I emphasized articles which have not yet been rated as part of the WP:1.0 project. That may help with tagging. Hope this is useful. Oleg Alexandrov (talk) 03:03, 15 May 2007 (UTC)

Very much so, I will get on these first--Cronholm144 03:10, 15 May 2007 (UTC)

I agree this is very useful, thanks Oleg :) Of course it is not a perfect metric, as well-linked articles are more likely to be in good shape, and therefore less in need of help. So it is definitely worthwhile (though very boring, sigh) to go through all of the articles. Probability and statistics is particularly under-represented in the assessment scheme. Is there a champion out there? Geometry guy 19:53, 15 May 2007 (UTC)

Differential equations

A recent edit of Differential equation expanded the article by adding a section Rise in importance during 20th century. I believe that it's a wrong article for this type of material (or wrong material for this type of article?), my concerns are summarized here. Can some experts in differential equations and/or numerical methods, please, take a look? Arcfrk 01:43, 17 May 2007 (UTC)

Relations on a set of three elements

I wonder, what do people think of Relations on a set of four elements, Relations on a set of three elements, and Relations on sets of two elements and less. Surely a lot of work has gone into them, but is such content encyclopedic? Oleg Alexandrov (talk) 04:52, 16 May 2007 (UTC)

They provide simple concrete examples of e.g. partial orders, total preorders, reflexive and irreflexive relations, etc., and also which combinations of properties are possible (at least for these small sets). For an active reader it is not too difficult to verify everything. (If something is unclear for the readers, you are welcome to add clarifications, of course. If something is unclear for yourself you can ask on the talk page.) The overviews can give a lot of insight. I do not see why they would not be encyclopedic.--Patrick 06:57, 16 May 2007 (UTC)

I agree that the content is pretty good but it may be a violation of WP:NOT#INDISCRIMINATE. Specifically number 6 which states that:

Textbooks and annotated texts. Wikipedia is an encyclopedic reference, not a textbook. The purpose of Wikipedia is to present facts, not to teach subject matter. It is not appropriate to create or edit articles which read as textbooks, with leading questions and step-by-step problem solutions as examples. These belong on our sister projects Wikibooks and Wikisource

Perhaps the content of this articles could be condensed and placed into the Relations article as an alternate solution.--Jersey Devil 08:04, 16 May 2007 (UTC)

Except for the "See also" links at Transitive relation, the present collection is a mini-walled garden of orphaned articles with names that are totally implausible as search terms. Concrete examples of various types of relations, as well as information on their counting sequences, is useful if provided at the respective articles. Just like (for example) Strict weak ordering has a section The number of weak orders (meaning: on a finite set), Binary relation could have a section "The number of binary relations (on a finite set)" to which these redirect. Although the corresponding sequence is in OEIS (sequence A002416 in the OEIS), it is not identified as such, so apparently not terribly notable as such, but such a section could contain a list of See also's, like for example to Strict weak ordering#The number of weak orders.  --Lambiam^Talk 09:55, 16 May 2007 (UTC)

The textbook claim may best be countered by regarding these articles as classification results. However, because the validity of this content could easily be challenged (e.g. as WP:OR, even though these are elementary verifications), it is vital that sources are provided. Also, the articles could usefully be merged under a more helpful title, reorganised, and written in a more encyclopedic tone. Geometry guy 10:58, 16 May 2007 (UTC)

I think merging all this into Relation (mathematics) would not be appropriate, as this verbose descriptive stuff would overwhelm the Relation (mathematics) article which should focus on the concepts only and a few examples. Oleg Alexandrov (talk) 15:05, 16 May 2007 (UTC)

That was my concern too (it would be the article binary relation, by the way). I started with a section of transitive relation, but for the same reason I split it off.--Patrick 15:11, 16 May 2007 (UTC)

I decided to nominate these pages for deletion as unencyclopedic. The deletion debate is at Wikipedia:Articles for deletion/Relations on a set of four elements. Oleg Alexandrov (talk) 04:38, 17 May 2007 (UTC)

Just to clarify my previous comment: I was referring to merging these articles with each other, rather than into any existing article. I'll raise this at the AfD. Geometry guy 12:25, 17 May 2007 (UTC)

Combinatorial mathematicians have spent quite some effort on counting various types of relations, and it would be possible to base a separate article on that, but who is going to write it? The approach I outlined above is still quite feasible.  --Lambiam^Talk 07:43, 17 May 2007 (UTC)

I agree with Lambiam; Patrick has now added a section Binary relation#The number of binary relations, sourced using OEIS. It seems to me that a fair amount of the material from the three articles could be used to provide a main article for this section (so that it does not overwhelm Binary relation), perhaps called Binary relations on a finite set, and sourced in the same way. Geometry guy 12:25, 17 May 2007 (UTC)

Articles listed at Articles for deletion

• Relations on a set of four elements (AfD discussion)

Please contribute to the discussion. Uncle G 09:05, 17 May 2007 (UTC)

See also Wikipedia talk:WikiProject Mathematics#Relations on a set of three elements above. Geometry guy 12:07, 17 May 2007 (UTC)

Collaboration of the "Week"

I don't mean to be a nag, but Theorem has been the CotW for at least a month. I think that participation in this collaboration had been a little spotty. We could rename it Cot-month or we could get theorem to FA. In any case I am tired of looking at theorem every time I log on and feeling guilty about the article :(. What do you think?--Cronholm144 05:44, 13 May 2007 (UTC)

See also the last time this was being discussed: Wikipedia talk:WikiProject Mathematics/Archive 24#Wikipedia:Mathematics Collaboration of the Week.  --Lambiam^Talk 07:19, 13 May 2007 (UTC)

It looks as if some good ideas were thrown out, but that none of them were acted on. Perhaps the s/election of a coordinator would be a good start.--Cronholm144 07:32, 13 May 2007 (UTC)

I would say that the Theorem CotW has been one of the better ones, the article has developed from Stub to Start or possibly B-class. In the first week very little happened and it then got a major reworking from GeometryGuy plus a couple of others.

In light of this I think a week is too short a time for people to give a particular article much attention, a month seems a more reasonable time frame. If its longer than that things get sluggish.

Yes a new cordinator would be good, fancy a job? --Salix alba (talk) 08:04, 13 May 2007 (UTC)

Who me? or Lambiam. All I would be good for would be bothering people on their talk pages. Lambiam, Geometry Guy, Salix, Oleg, Jitse, etc... would do a better job of it. (If they don't want it then maybe...) thanks for the consideration.--Cronholm144 08:18, 13 May 2007 (UTC)

Wikipedia runs on volunteers, so the best way to get something done is to do it (or organize it) yourself. You noticed something that moved you to speak, therefore you are the obvious choice for coordinator. :-) --KSmrq^T 10:10, 13 May 2007 (UTC)

All right then, I gratefully accept. I will get working on it in roughly 8 hours. I will keep my promise about soliciting help from everyone. I will see you on the talk pages;)--Cronholm144 10:21, 13 May 2007 (UTC)

Bothering other people is exactly right as a job description, so we have a perfect fit. :) Good luck. By the way, perhaps someone (K.?) should tell User:Meekohi that we are grateful for his long period of service as the self-proclaimed moderator of the Mathematics Collaboration of the Week project, but that we have managed to find a self-proclaimed replacement, so that he can retire as such and enjoy his regained freedom to give his undivided attention to actually improving articles, rather than having to spend time on moderating such activity.  --Lambiam^Talk 13:42, 13 May 2007 (UTC)

Update:

Good news everyone, for the first time since I have been here an article has received more than 4 votes:). This of course means that the time to change the article has finally come. The winner is Mathematical Physics a top importance article and one of the 7 or so main categories here at the WP:WPM. I am proud to report that this article, as per the COTW requirements, is in dismal shape (another nominee by the way), so making significant improvements should be easy. I would welcome any and all to help out with this article. Also, on a more technical note, I don't know how to change the template, so if someone could do that for me I would be very appreciative. Thanks to all--Cronholm144 01:01, 16 May 2007 (UTC)

Done: for information, see Wikipedia:Mathematics Collaboration of the Month#Templates involved in MATHCOTM; the last two inks contain the current and previous collaborations, so you just edit the contents of them. Geometry guy 01:32, 16 May 2007 (UTC)

I've now given the page a spring clean. In particular, I've moved around some of the templates, which were all over the place before. Also the page seemed to contradict itself about the rules, so I've attempted to rephrase them. Of course, The Coordinator is the ultimate arbiter ;) Geometry guy 11:00, 18 May 2007 (UTC)

POLICY DEBATE: Use of mathematical and other examples in articles

I have opened a debate on the use of examples in Wikipedia articles (mainly focusing on computer source code and mathematical proofs, equations, etc.). It seems to me that many examples currently in Wikipedia violate Wikipedia policy, so I believe we need to either clarify or change the situation. Depending on the result of the discussion, this may result in a number of examples being summarily removed from articles!

Please reply there, not here, if you wish to contribute.—greenrd 11:08, 18 May 2007 (UTC)

I know you say to reply there, not here, but this seems a more apt place for my comment. I don't think it is appropriate to lump together mathematics examples with source code. Mathematical examples are absolutely essential in many articles. Without them, some abstract mathematical statements are often completely useless. Furthermore, examples help to supply a context for much of mathematics. For instance, the formal definition of a locally ringed space is utterly meaningless without an appropriate algebro-geometric context. The Atiyah-Singer index theorem is completely motivated by the examples which it generalizes. The list goes on...

Computer source code is, generally, an implementation detail. See, for instance, quicksort where there are several versions of the algorithm (admittedly a bit different) written variously in an Algol-like pseudocode, C, and a dialect of Pascal. In this case, I would say that the use of examples vis-a-vis source code clearly goes to far. The various versions of the algorithm should be as implementation-independent as possible, and lengthy (the C example takes over a page of scrolling to get through) source snippets in a particular language don't seem to be helpful in illustrating the differences. They are rather, it would seem, cut-n-paste tidbits for programmers a la various coding tutorial websites out there in cyberspace.

So mathematics examples are certainly of a different character than source code. They aren't a mere implementation detail. Your threat of summary deletion is troublesome to me. It potentially suggests that editors with only a vague understanding of the subject matter are going to start taking the axe to mathematics articles. Many of our articles are quite specialized, and edited by people experts in their respective fields of study. Granted, some of these could do with a bit of pruning here and there. But I suggest leaving it up to the qualified editors to decide what should go and what should stay (and what should be expanded). Implementing a broad "totalitarian" policy is definitely not the way to go. Silly rabbit 12:19, 18 May 2007 (UTC)

Need help with Wadge hierarchy and related articles

The Wadge hierarchy stub needs help from an expert. Wadge game needs an article or a section in Wadge hierarchy. If these topics are better covered in other articles, then a paragraph in another article with a merge/redirect or blank/redirect may be in order. Disclaimer: I am not a mathematician. davidwr ^09f9(talk) 15:38, 19 May 2007 (UTC)

Category:Jewish mathematicians CfD

This category was recently deleted as part of the general deletion of Category:Mathematicians by religion. However the case of Category:Jewish mathematicians was put forward for deletion review and its deletion was overturned. Consequently it is now being considered for deletion again. I encourage members of the maths project to contribute to the discussion here. Geometry guy 18:01, 14 May 2007 (UTC)

There is possibly enough consensus to delete this category, which would be in line with the deletion and/or absense of similar religious/ethnic categories for mathematicians. However, there are users with no particular expertise who stop by at CfD's like this with a political agenda. Can I please encourage everyone here to look at the page and express their view. The outcome really does have the potential to affect the quality of life for many editors here, as the recent discussions over Georg Cantor illustrate. Please remember, though, that this is not a vote: read the contributions of other editors and express your view with comments and justification. Geometry guy 23:33, 15 May 2007 (UTC)

Are you sure that it makes any difference? I have spent enormous amount of time analyzing the previous discussions and their outcomes, and came to the conclusion that people with this political agenda and no particular expertise are very persistent, and have the proven ability to bring this category back to life. To me it appears to be a canonical example of метать бисер перед свиньями. Comparatively speaking, I would prefer reverting vandals at Geometry or Algebra, at least, it's more efficient if just as hopeless. Arcfrk 01:05, 16 May 2007 (UTC)

For the sake of clarity, the Russian text above means "throwing pearls to the pigs", which is is used in English too, I think. Oleg Alexandrov (talk) 02:29, 16 May 2007 (UTC)

"Pearls before swine" but I think my generation is losing this and many other great colloquialisms,:( Anyway I don't believe we should ever allow this kind of thing to encroach on the wonderful place we have created here, fight to protect it, lest we lose it.--Cronholm144 03:12, 16 May 2007 (UTC)

A twist of irony that; here's the line as it appears in the King James Version of Matthew VII, verse 6:

Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.

In generations past, reading literacy was often built on a text found in many homes, so such phrases were familiar; but Matthew may have been less popular in Jewish homes.

As for the obsession some have to classify people according to Jewishness, I have expressed my sentiments in the Cantor discussion. Next I suppose we'll be forced to nationalize Leonhard Euler, who spent more time in Russia than in Switzerland. And after that we'll be counting toes. It's an idiotic waste of time; but the human race, like a human infant, is slow to mature. --KSmrq^T 04:01, 16 May 2007 (UTC)

I take your point, but I think it could. Not only are there essentially no other similar mathematics categories, but also there are essentially no similar subcategories of Category:Jews by occupation: Category:Jewish scientists exists, but there is no Category:Jewish physicists, Category:Jewish biologists, Category:Jewish chemists, and so on. These persistent people have a general goal, but not a specific focus. If this the maths cat goes away, there is no more reason to recreate it than any of these other subcats. My best guess would be trench warfare at Category:Jewish scientists, but even that would leave many of us a little more in peace to get on with improving maths articles. So please don't be despondent! Geometry guy 01:59, 16 May 2007 (UTC)

To KSmrq: Thank you for the full quotation. It is one of many good sayings from Jesus's Sermon on the Mount.
To People in General: Please provide translations to English for any quotations you provide in a foreign language (except perhaps French which is so close to English). JRSpriggs 10:26, 16 May 2007 (UTC)

Arab mathematicians

One of the arguments that keeps arising in these debates is the existence of Category:Arab mathematicians, which seems superficially similar to Category:Jewish mathematicians, at least to those who can't be bothered to go and see what is actually in the category. Of course, the arguments for this similarity are flawed, but it is not as easy as it could be to squash them for a couple of reasons.

1. At present Category:Arab mathematicians is a subcategory of Category:Mathematicians by nationality, and does not contain many important Category:Persian mathematicians. This suggests it could be renamed Category:Arabian mathematicians to eliminate the controversy. In that case, though, it should be about mathematicians of Arabia. And essentially it is up until the time of Al-Jayyani (989–1079). From then on, though, the listed mathematicians all lived in what was then Al-Andalus, and is now Spain, or (in a couple of cases) Morocco.
2. In contrast to Jewish mathematics (and Category:Jewish mathematics), there does exist Arabic mathematics (and Category:Arabic mathematics). However, the first of these links redirects to Islamic mathematics, and Category:Islamic mathematics is offered as the "correct" category for the second (does this need a CfD?). This seems an unfortunate choice to me!

These are rather thorny issues. I have raised the second one at here, also partly because I think there has been a misunderstanding about the meaning of the adjective "Arabic", which doesn't refer to people (that would be Arabian or Arab) but language, literature and culture.

For the first issue, is it worth creating Category:Al Andalus mathematicians or are there other ways to clarify this point? Geometry guy 17:16, 16 May 2007 (UTC)

In my opinion both Category:Arab mathematicians and Category:Persian mathematicians should be deleted. Modern day mathematicians are better placed in Category:Iranian mathematicians, Category:Saudi Arabian mathematicians, Category:Egyptian mathematicians, etc. In the case of historical mathematicians it only creates an artificial and unnecessary split (no to forgot that a significant portion of related biographies can't, with certainty, be placed in any one of them.) I've categorized most of the biographies currently under those two categories in Category:Arabic mathematics/Category:Islamic mathematics but this has the drawback that it doesn't separate the biographies from the other topics. —Ruud 17:39, 16 May 2007 (UTC)

P.S. Certainly not all "Islamic" mathematicians after 1079 lived in Spain. See for example Jamshīd al-Kāshī or Sharaf al-Din al-Tusi. —Ruud 17:39, 16 May 2007 (UTC)

Clear, but both of the examples are Persian. Just out of interest, can you come up with Arabian examples? Geometry guy 19:26, 16 May 2007 (UTC)

Al-Khalili and Ibn al-Shatir came from Damascus. Not sure if that would make them Arab or Syrian, though. —Ruud 20:32, 16 May 2007 (UTC)

There are some more from that period in Category:Spanish mathematicians, I think, including at least one Jew. I am in favor of a category that collects together mathematicians from the Arabian mathematics period (whatever you want to call it) and that has a name that includes islamic Spain but unambiguously excludes modern mathematicians from the same places. —David Eppstein 17:30, 16 May 2007 (UTC)

I agree, this is a possible way forward. It almost surely not a good idea to identify such "arabic mathematicians" as Spanish, although the whole issue of geographical vs political nationality is also rather thorny. Geometry guy 19:26, 16 May 2007 (UTC)

If there is a category for mathematicians from the Islamic/Arabic civilization, wouldn't "Category:Arabic mathematicians" be a better name? To me the primary meaning of "Arab" refers to ethnicity, and "Arabian" to the geographic area. "Arabic", on the other hand, refers foremost the language and its script, which was used as the Lingua Franca in which the mathematicians of Islamic civilization wrote their works, just like scientists in Christian civilization used Latin.  --Lambiam^Talk 19:06, 16 May 2007 (UTC)

I tend to agree with that: also Arabic refers to literature, which is quite appropriate in this case. Geometry guy 19:26, 16 May 2007 (UTC)

Also see the two quotes at User:Ruud Koot/Arabic mathematics#Terminology. Here Toomer argues for the term "Arabic mathematics" and Berggren for "Islamic mathematics".

Outcome

Editors here might like to know that the outcome of the CfD for Category:Jewish mathematicians is deletion. I would like to thank others here for taking the trouble to comment at this CfD and thus express the view of general mathematics article editors. The discussion was one of the longest I have seen, so the weight of good argument that editors here contributed was very important. Geometry guy 10:56, 20 May 2007 (UTC)

Who are the most best editors around here?

Hi, I'm looking for a small number of Wikipedia editors in the Mathematics area who are well-qualified, well-respected, and have high standards. This is for a new project that needs such talents; just now I'd rather not advertise the details. Please tell me some names, including perhaps your own if you fit the description. Thanks. --Zero^talk 10:46, 19 May 2007 (UTC)

Methinks mostest editors went a-scurrying after reading this ungrammatical, error-filled request. linas 15:52, 20 May 2007 (UTC)

We're not such a judgemental lot are we? It looks more like a case of Groucho Marx to me: "I don't want to belong to any club that will accept me as a member" :) Geometry guy 16:33, 20 May 2007 (UTC)

Can people who don't edit under their real name rate articles?

At Talk:Cross product, Edgerck reverted Geometry guy's rating of that article, on the grounds that Geometry guy has an anonymous identity and since Edgerck does not agree with the rating anyway. Comments? Oleg Alexandrov (talk) 15:44, 19 May 2007 (UTC)

No, no, no. Wikipedia does not require that users reveal their real identity or credentials (it's not acceptable to fake either, but that's a separate issue). Should I not be able to rate articles because I edit under a pseudonym? Disagreeing about the rating is one thing, but he does not automatically have authority because he uses a real name. —METS501 (talk) 15:48, 19 May 2007 (UTC)

Changing the rating because you disagree is fine (although discussion might be helpful). Removing the whole template because someone uses a pseudonym (not the normal meaning of anonymous in a Wikipedia context anyway) suggests that either there is something else going on, or Edgerck is not used to the whole procedure. JPD (talk) 15:53, 19 May 2007 (UTC)

Geometry guy is an established, regular, and seemingly knowledgeable editor of math articles here. To me that carries a lot more weight than knowing or not knowing his real-life name. —David Eppstein 16:30, 19 May 2007 (UTC)

Of course! Anyone can rate articles, and anyone can change ratings. That is the whole spirit of wikipedia! One of the reasons I edit anonymously is that I do not want any of my edits to carry a stamp of authority. They should all be judged individually. I am rating a lot of articles at the moment, and am going to make mistakes (well, we all make mistakes: even a genius like Grothendieck can suggest 57 as a prime, as an anonymous IP editor pointed out to me recently). If anyone disagrees with any of my ratings, change them. Even better, add a comment and sign/date the new rating. I would only ask that they have a quick look at Wikipedia:WikiProject Mathematics/Wikipedia 1.0 first to get a feel for the system. Geometry guy 17:55, 19 May 2007 (UTC)

Hello all. Looks like people here did not read my original comment in Oleg's page. I commented that in view of the known identity abuses at WP, an user who wishes to remain anon (which they do for their own benefit) should not venture into questionable edits. I think this could be a self-enforced rule, for fairness. This is not just about Gg's rating. To be relevant, ratings need to be 1) based on a statistically significant number of opinions and 2) provided by unique, qualified (even if anon) participants. This is standard stuff. Gg's rating goes against (1) and (2).

On the topic of anonymity, let me comment in general (not making an instance on Gg's case). I am a believer in the need for anon discourse -- for example, in political areas. But, given today's principle of academic freedom, I can't see a reason for anon discourse in physics, math, or biology, for example. And, as anyone can see, the "stamp of authority" argument is not a barrier for online questioning. So, on the contrary, in these areas I see reasons otherwise, with people in WP and elsewhere (eg, usenet groups) using anon discourse and taking pseudonyms with bogus academic qualifications in order to advance crank, niche or copyrighted material under the cloak of an IP number or nickname.

There are also people who seem "well qualified" in WP, but in discussion with them, or reading their edits, their content reveals otherwise. Users who like to patrol some articles in order to ensure conformance with their niche or particular views, with ensuing edit wars if contradicted, are usually not quite open about who they are, as their opinions and methods may backfire.

In summary, I think that transparency (which can be called sincerity etymologically) would go a long way in preventing the distortions seen in WP today, with identifiable individuals that would stand behind their opinions.

Those that wish to remain anon should by all means be allowed to do so, in the name of tolerance, but since they do this for their own benefit they should also use some measure of self-restraint in what they can do or not. While it's certainly fair for anon users to edit and provide opinion, it may not be as fair for them to place themselves as judges of opinion.

I hope this is useful.Edgerck 19:30, 19 May 2007 (UTC)

A fair enough view (the people behind Citizendium also think somewhere along these lines). But restricting anon editing goes against the spirit and policies of Wikipedia however. Not much can be done about this, I guess, unless Jimbo himself has a change of mind (which is unlikely, I think). Oleg Alexandrov (talk) 19:36, 19 May 2007 (UTC)

Oleg: A minor nit. As above, I am not for restricting anon editing, even though (just from the view point of information reliability as used in scientific research and journalism, for example) verifiable sources are a basic tenet for reliance on information (trust). What I am for is for self-restricting anon ratings, for the reasons above. Anon users should not use their invisibility cloak if they wish to judge others. Edgerck 19:45, 19 May 2007 (UTC)

I still don't see that you have explained why we need to know the person's real name in order to judge their reliability as a WP editor, or why the rating process is so critical and inflammatory that it must only be handled by persons of known reliability. —David Eppstein 19:50, 19 May 2007 (UTC)

David: "Ratings" is one example of what I would call trust asymmetry in WP today. It's easy to verify that anon editing is actually a recognized problem in WP -- just see the WP policy for verifiable sources, to see the basic contradiction. Why wouldn't there be a need for authors to be verifiable if references should be? However, one can argue that the benefits of anon discourse trumps the rule for verifiable sources. That's acceptable in a balance of interests for what WP is. But using anonymity to judge others seems to be unjustifiable under the same balance of interests. It seems murky and open to distortions, for no real benefit. Reliance on information is more than just what the record says for itself -- there must be independently verifiable channels of information that provide the trust channels for that record.

On another topic, in addition to the crank and niche views, it's possible that WP has a large Intellectual Property liability under the current anon editing guidelines. This will eventually surface. Edgerck 20:11, 19 May 2007 (UTC)

Maths ratings are not about judging others, they are about assessing articles: those who disagree should check out WP:OWN. Geometry guy 20:18, 19 May 2007 (UTC)

I certainly did read Edgerck's remark on Oleg's page before commenting here: I usually try to check out where a fellow editor is coming from before I contribute. The comment "an user who wishes to remain anon (which they do for their own benefit) should not venture into questionable edits" suggests Edgerck hasn't actually read my post immediately above his, in which I explicitly state one of my own reasons for remaining anon.

The real abuse is not anonymity, but using unverifiable claims of authority to support edits. I don't do this. I do mention (for those who are interested) that I am a professor of differential geometry on my user page, but I explicitly state that I do not want anyone to take this into account when judging my edits. After all, how does the average WP editor know that User:Edgerck is the famous Ed Gerck who

received his doctorate in physics (Dr.rer.nat.) from the Ludwig-Maximilians-Universitaet and the Max-Planck-Institut fuer Quantenoptik in Munich, Germany, 1983, with maximum thesis grade ("sehr gut"). He also has titles of Electronic Engineer (1977) and Master of Science (1978) from the Instituto Tecnologico de Aeronautica (ITA/CTA), Brazil.

and then went on to

work in information security and election integrity received worldwide press coverage by The New York Times, Le Monde, O Globo, Forbes, CBS, CNN, Business Week, Wired and USA Today.

I'm not questioning that he is who he says he is, I am just pointing out that an eponymous username and a list of credentials doesn't help prevent abuse. As Oleg points out, Citizendium is the place for those who want verifiable credentials. Here the policy is: judge every edit on its own merits, and be bold. Don't complain about other user's edits: fix them!

Finally, as for maths ratings, my point of view is that a good result can be achieved by a process analogous to simulated annealing in which many users contribute by adjusting ratings where they think they need to be changed. If Edgerck prefers these ratings to be produced by a statistically significant number of expert opinions, he should go ahead: there are only about 10000 articles still to assess, so it shouldn't take him and him team of experts too long. Geometry guy 20:18, 19 May 2007 (UTC)

Forgive me if this is repetitive. This edit is the result of an edit conflict.

"There are also people who seem "well qualified" in WP, but in discussion with them, or reading their edits, their content reveals otherwise." I would argue that in the case of Geometry guy this is precisely the opposite. He has established himself as a very skilled editor and is an active editor in the community. To my knowledge, none of his edits have been questioned except for the WP 1.0 ratings, and considering that he has over 1000 of these it seems inevitable that someone would disagree with B vs start or a high ve. mid rating, I know that I have been rating quite a few articles lately and have made more mistakes on average than Geometry guy. Rather than assuming that an anonymous editor is unqualified I think a better litmus test (and the one that I think is usually used here at WP) would be to judge the editor on the quality of their edits.

Another example is the friendly exopedian that has been patrolling Calculus and Derivative lately, He has made excellent comments and improved the articles significantly, yet he simply doesn't want to edit under anything but an IP. The W.P. rating system is rather simple, field (this can usually be ascertained by a layman) Importance(more difficult, especially if you are not experienced in said field, this could be a valid change, I know that when I make my edits this is the most frequently changed) Class(this is tricky for articles that cover the topic well, but the topic just isn't that large, but in most other cases assessing the class is rather simple as well). The goal of all these assessment is to place all the important math articles under the same proverbial roof. If you have a problem with the rating, go ahead and correct it, these templates are for use by the editors of the articles so the occasional mis rate doesn't last long assuming the editors are active and doesn't affect the casual reader. --Cronholm144 20:25, 19 May 2007 (UTC)

Furthermore, these ratings are not for casual readers (they are placed on the talk page): they are for other editors. Geometry guy 20:35, 19 May 2007 (UTC)

When we set up the maths rating process it was designed to be light weight, lacking on buracracy. Any editor can add a rating, if a another editor disagrees with a rating they can ammend it. If there is disagreement then it should discussed on the articles talk page in the first instance, just as any question about the content of the article. As yet I've seen nothing which explains why you disagree with the rating.

If this relates to a specific problem with the article then a discussion on the talk page might help to improve the article. There is even a posibility to edit Talk:Cross product/Comments if there are a comment you wish to make to support a given rating. --Salix alba (talk) 20:43, 19 May 2007 (UTC)

My opinion is above -- the rating system is flawed as it stands, especially if you consider anon rating. Hope this helps. Edgerck 21:09, 19 May 2007 (UTC)

If you believe that, then you should believe that Wikipedia in general is flawed, as it is based on principles allowing anonymous editing of anything, including ratings. Why not join a project like Citizendium that has a more compatible philosophy to yours? —David Eppstein 21:17, 19 May 2007 (UTC)

David: This is getting long, so I'll be brief. Please do not tell people what they should believe. As I wrote above, my opinion is that anon editing is acceptable in a balance of interests for what WP is. But using anonymity to judge others seems to be unjustifiable under the same balance of interests. Hope this is useful. Edgerck 23:01, 19 May 2007 (UTC)

For lower grade articles Stub to B+ the system has served us well to date. GA, A and FA ratings have a more formal process to go though to gain those status. If you think the article deserves a higher status then by all means put it forward to WP:GAC, Wikipedia:WikiProject Mathematics/A-class rating or WP:FAC. --Salix alba (talk) 21:40, 19 May 2007 (UTC)

break it and then fix it? It may be better to have a merit system to begin with. Asking anon users to voluntarily refrain from rating (but not editing!) does not seem to be an undue burden on the informal process. Edgerck 23:01, 19 May 2007 (UTC)

Well it seems that your opinion is not shared by the majority of users here and is not in line with WP policy. So, while it is fine that you believe that, it is not fine to perform reverts in that vein until such criteria is adopted as general policy here. I think the consensus is that you should change the ratings that you don't agree with, rather than revert them.--Cronholm144 23:10, 19 May 2007 (UTC)

I think several people, including me, find your insistence on this rather bizarre for a very simple reason. There are several levels of importance in editing (I will give a rather rough description to make the point). The most important is editing the article itself, creating or modifying articles. Significant errors, unseemly promotion, dubious material, libelous content, can all be introduced this way. Next level of importance contains things like categories or lists. This is because the usual reader can see if a mathematician is categorized (by the category system) as a Jew or bisexual (very contentious matters for whatever reason). Among even less important things are whether a stub gets marked as a "topology stub", "geometry stub", "math stub", or whether the stub marker goes in a section, or should go at the top, or whether a technical tag goes on the article or its talk page. Among the least important is whether a WikiProject tag on an article talk page should say "mid importance", "low importance", etc. or have a grade of "B" or "C", etc. This is the least important because it in no way affects the content of the article and is not even seen by a usual reader. This is a tag for people in a WikiProject. If you don't want to participate, that's fine (although I recommend you do so), but it's designed by other people for their use. Also, I think once you learn about the rating system, you will see that the editorial judgment of whether a topic is of "mid importance" or "top importance" is not only not as important as editing the article itself, but a much easier editorial judgment to make (and correct) than restructuring and changing an entire article. I have no idea what the Atiyah–Singer index theorem is, but I know it is very important. My ignorance prohibits me from changing that article, but you can imagine a less restrained person, after reading some pop-sci article about it, changing the lede section and mucking the whole thing up. That's what you should be worried about, not whether some helpful anonymous person who has a history of accurate mathematical contributions marks your article as "mid importance" for some maintenance purpose. --C S (Talk) 09:36, 20 May 2007 (UTC)

Edgerck is a relatively recent user here and the ways of Wikipedia seem rather alien at first. For example, if in real life, someone does something that you disagree with, then the polite thing to do is to go to them and explain (preferably nicely) what you thought they did wrong. In Wikipedia this is not the right response: instead you should undo or change what was done, preferably with a friendly and explanatory comment in the edit summary. If this change is reverted, only then it is time to go to talk. Since this goes so much against normal real life interaction, it is not surprising that in practice users turn to talk before it is really necessary.

The mathematics project is far better than most of Wikipedia in this regard, but still several users have come to my talk page when all they really needed to do was change the rating. I have been gathering responses here. I understand the tendency to complain instead of fix, talk instead of do, and am certainly guilty of it myself, but this is a wiki: all mistakes can be fixed! It is a pity that hard-working editors rarely receive encouragement and thanks, but often receive criticism for their inevitable mistakes.

Anyway, Edgerck has expressed his opinion, and most people here have disagreed with it. It seems to me that it is time to move on. In fact I think Edgerck himself would like to move on: see e.g. this recent diff. I would love to receive an apology, but I am happy to move on as well. Geometry guy 23:50, 19 May 2007 (UTC)

Apology? Do anonymous users get offended also? :) Oleg Alexandrov (talk) 00:12, 20 May 2007 (UTC)

If an anon falls in the forest and nobody is around, does anybody care?

Not at all, but they love good humour, just like regular editors! By the way, if anyone wants to see an example of what can go wrong with unfriendly edit summaries or going to talk too soon, take a look at this unedifying exchange ;) Geometry guy 00:23, 20 May 2007 (UTC) PS. And many thanks to Chan-Ho for deftly inserting the above forest line into the discussion! Geometry guy 12:29, 20 May 2007 (UTC)

As a pseudonymous (that is the better term, rather than anonymous) editor, I do not intend, because of my pseudonymity, to limit my editing in any way. Paul August ☎ 03:46, 20 May 2007 (UTC)

Since we are on the anon user issue, could please anyone tell me their opinion whether the WP guidelines for verifiable claims apply also to anon user pages? Thanks. Edgerck 07:45, 20 May 2007 (UTC)

No. Wikipedia:Verifiability talks consistently about articles, and user pages are not articles. See Wikipedia:User pages for some things that you cannot have on your user page. I don't think it says so explicitly, but you're also not supposed to lie. -- Jitse Niesen (talk) 08:18, 20 May 2007 (UTC)

Correct; it also would be counterproductive to require all comments on talk pages to be verifiable. However, we accumulate reputations; see below.

And please, learn the Wikipedia distinction between a truly anonymous editor (someone editing as an IP not logged in to an account), and most other editors (an editor logged in to an account which does not reveal their real-world name). Yet somewhat ironically, an IP can reveal a great deal about the source of an edit!

In the academic world, it is not unusual for those reviewing a paper to do so blindly, without knowing the identity of the author(s). The idea is that the contents should be judged on their merits alone, not on the status or connections of the source. Wikipedia does not demand that contributors use their real name, which in some cases could have terrible personal consequences. However, every account builds a history of contributions, and it usually does not take long to get a feel for the strengths and weaknesses of an editor.

Wikipedia is distinctly different from a peer-reviewed journal. Some of those differences cause difficulty. For example, a 16-year-old student who is just beginning to master basic algebra has just as much right to edit an article on integral calculus as a college professor who regularly teaches the subject. Both are also free to submit a paper to a journal, but Wikipedia policy makes it rather difficult to give more weight to the professor on this topic and to quickly discard the misconceptions of the student.

Or consider the case of Carl Hewitt, an emeritus faculty member of MIT who made important contributions to computer science. He created an account here under his own name, and was accorded all due respect until it because clear that his edits were not consistent with current mainstream concensus, and were becoming highly disruptive. Arbitration was requested when dialog failed. He proved to be a very bad Wikipedia editor.

Thus I would argue that your concerns about "anonymity" are misplaced. The on-line world has a history and culture of pseudonyms, which I expect to persist at Wikipedia. Credibility and authority are linked to identity in the real world through behavior and association; the same is true here.

Wikipedia is a strange and awkward adolescent, and none of us entirely understand what it is, what it will become, and how best to guide it. We appreciate your interest and participation, and invite you to continue, even though we find this proposal unacceptable. --KSmrq^T 09:30, 20 May 2007 (UTC)

Of course, if a user identifies herself as a persona (a legal term) then that user could be liable for lies, impersonation and false claims. But such questions may not apply to an anon user. As a fictional character, an anon user can certainly claim academic credentials and positions that don't actually exist -- and simply say it was all a fantasy.

Now, why would an anon user who says she is anon because she does not to want any of her edits to carry a stamp of authority, claim an academic credential and a stamp of authority in her user page, and mention them as a weight in public discussions? The same questions, thus, seem to surface again, even for an anon user. Edgerck 08:50, 20 May 2007 (UTC)

One thing I've regretted a few times is using my real identity on Wikipedia. In any discussion with an imbecile, you will come off looking bad, no matter how well you manage to avoid falling prey to insults. Even if some onlooker (as these Wikipedia discussions will no doubt turn up in a Google search of your name) thinks you behaved well, s/he will wonder why you spend so much time arguing some lame, minor point with some 13 year old instead of working on research. I wonder how silly I will look if a potential employer finds this discussion; answer: probably not half as silly as if s/he found some other of my discussions. I think a number of people that are "Internet-savvy" realize these things quickly and are anonymous for that reason. Also, the value of personal security (of yourself and those around you) is important. I had a bad incident where somebody living in fairly close proximity to me sent threatening emails to me and some of those around me. I can't help but feel bad that some people had to endure this kind of thing because I have a hobby like editing Wikipedia. I refrain from editing truly contentious topics for this very reason, although it can be strangely difficult to avoid. --C S (Talk) 10:12, 20 May 2007 (UTC)

Shortly after the recent tragic shooting at Virginia Tech, attempts were made to mention it in the articles on the two guns identified. There were some strong opinions about whether that was appropriate, and one editor went seriously over the line in his comments to many here. Eventually he told one woman, an admin who had cautioned him, that he lived near her, and then he threatened her life. A quick decision was made to permanently ban him from Wikipedia, and the worst of his remarks were permanently deleted (they will not even appear in histories). I would be offended by a suggestion that the threatened admin have restricted rights because of a reasonable choice to hide personal information in order to avoid such risks.

Or consider editors in Burma or Tunisia or certain other countries where the Web is censored. If they edit openly, they may risk imprisonment or assassination.

Editors choose what to expose and what to reveal, for many different reasons. The on-line community generally does not distrust partial anonymity, no more than we would mistrust someone for having a lock on the door.

And, frankly, if you really are the Ed Gerck (Ph.D.!) described here, I find your comments hard to take at face value. Perhaps they are a crude attempt to probe how trust works on Wikipedia? --KSmrq^T 12:46, 20 May 2007 (UTC)

If you have a specific question for G-guy, why don't you address him on his talk page? Instead of making vague insinuations here in a public forum(I am aware this is not a sentence).--Cronholm144 09:12, 20 May 2007 (UTC)

I apologize for my rudeness Ed, I was feeling grumpy and sleepy and thought that this issue had been put to rest. However this is no excuse for my actions. I violated my own wikipolicy and I am ashamed that I did not assume good faith. --Cronholm144 15:28, 20 May 2007 (UTC)

Thanks, Cronholm144. Your comment is framed in such kindness that I can only hope I can be of help to you in the future. Edgerck 15:38, 20 May 2007 (UTC)

P.S. G-guy's comment refers to the comment above this one

Thanks so much for accepting my apology.:) The thing that would help me most would be your continued involvement here, whatever form that may take. This little wikipedia community needs as many good editors as it can get. If you are up to it, your rating of unrated maths articles would be much appreciated, or feel free to contribute to the Mathematics Collaboration of the Month by voting or editing. These two have become my pet projects here. I am sure as you continue to make great edits. like you have at Cross product, you will develop a few pet project/peeves of your own. ;)--Cronholm144 16:05, 20 May 2007 (UTC)

Actually, I think I should be grateful to Edgerck for generating so much interest in mathematics article assessment! When I raised it recently at Wikipedia_talk:WikiProject_Mathematics/Archive_25#Mathematics_article_assessment, the silence was deafening. Unfortunately, because of the lack of response, this post got archived by the bot. I encourage Edgerck and others who missed that post to take a look. If only I had appreciated the benefits of controversy earlier; I could have created a sock-puppet account and started an edit war with myself, sigh ;)

Concerning the question: why would a pseudonymous user mention their career on their user page? Personally, I find it useful to know a little bit about other users, because it helps in communicating with them using a medium which is at best suboptimal. If the user did it to add weight to their edits, then they are certainly misguided. For one thing, it doesn't work. I don't know if Edgerck has tried using his credentials in this way, but he will probably find it is more likely to make other editors hostile than reverent. The ideal at Wikipedia is to judge each edit on its own merits and if editors are judged at all, it is purely on the quality of their edits. The fact that I mentioned my profession above added no weight to my comment. I have never used it to support my edits to maths articles and never will.

Concerning verifiability: there is no contradiction between anonymous users and verifiability. It is the article that must be verifiable, not the editor. Any statement can be challenged and removed if a reliable source is not found. It doesn't make any difference who produced the statement. Indeed in some ways it is better if the statement was made by someone with unverifiable identity/credentials, since then it can only be judged on its own merits! I know an editor who contributes only as an anon IP for precisely this reason.

Finally maths ratings. I repeat again, they are not judgements or referee reports or anything of the kind. They are an organisational tool. And, quite frankly, if anons and pseudonymous users restrain themselves, mathematics article assessment is not going to get done. I was rather disappointed by the lack of response to my previous posts on this topic; Edgerck may not realise that before this post, the maths rating system was in the doldrums. Now it is moving again. Geometry guy 12:29, 20 May 2007 (UTC)

Desirability for ratings to be signed and dated, on-page

I don't see a problem with ratings by users under their "noms-de-wiki". But what I think can be hard is ratings without any comment, date or signature (apart from buried in the edit history). Firstly, because it doesn't give any on-page indication as to how long ago the article was rated, as so how it might have changed since that time; and secondly, it can make it seem as if the article has been rated by an impersonal unarguable and unappealable "voice of God", rather than by a particular wiki-member of the project.

So could raters please add a name and a date into the comments space, even if they don't add a comment? Cheers, Jheald 09:55, 20 May 2007 (UTC)

Yes, ideally all maths ratings should be signed and dated, preferably with a brief comment on how to improve the article. However, there are many which have no such comments — see Category:Mathematics articles with no comments — and commenting takes time to do. I take the point of view that it is more useful to the project to have an important article rated without a comment than not rated at all. However, anyone who happens on a maths rating without comments has the following options:

1. They agree with the rating; then they can sign/date it, or even add a comment.
2. They disagree with the rating; then they can change the rating, sign/date it, and add a comment.
3. They can check the edit history to see who added the rating, go to that editor's user page and complain.

It is a pity that the third approach is often taken instead of the first two.

Concerning the "voice of God" point, I think there is some misperception about what maths ratings are for. They are not judgements; they are not for readers, but for editors; anyone can change them; anyone can comment on or sign them. They are aimed at directing future edits to improve our coverage, they are not "referee reports" on work done so far. Geometry guy 10:35, 20 May 2007 (UTC)

Further to this, Cronholm and I have managed to instruct AWB to allow us to leave comments or at least sign. The list we are working through is here: these are essentially the unrated articles on Oleg's list, and are ordered by the number of articles which link to them. Any AWB fans just need to save the source for the page in a text file to join in the fun. Geometry guy 12:06, 21 May 2007 (UTC)

Rather than grumble, I decided to take up my own suggestion and sign a few ratings. I went through the entire stub class, checking the articles, upgrading them to start class where appropriate, adding a (helpful, or often not so helpful) comment in a few cases, and signing and dating in general.

This moves the goalposts again of course, and there will undoubtedly be complaints about ratings without comments, but I am getting used to this. The number of unsigned/dated assessed articles peaked at nearly 1800 recently: it looks like it can be brought back down closer to 1000. Geometry guy 21:13, 22 May 2007 (UTC)

Update: after peaking at around 1800, the number of assessed articles without comments, signature or date has come down to a more manageable 709. Of course, most of these are just a signature and date, and many of the comments are bland, not particularly helpful, or possibly even tactless ;) ! Please feel free to replace these by something more useful. I would also point out that there is nothing to stop editors from assessing or commenting on articles to which they have contributed (even substantially): it is the article that is being assessed, not the editor! Geometry guy 16:50, 24 May 2007 (UTC)

Layout of the main assessment page

I think some overview of the assessment goals should be placed near the top of Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Assessment (which is linked from the {{maths rating}} template). When I first encountered these assessments, I was also a bit confused as to their purpose. I had to dig around a bit to determine that they are in fact a very good thing. An FAQ might also be helpful (if there isn't one already?). Silly rabbit 12:50, 20 May 2007 (UTC)

I'll update that page: it's original main use was a template to be transcluded onto other pages. The main page for the article assessment scheme is Wikipedia:WikiProject Mathematics/Wikipedia 1.0, but I can improve the "noinclude" information on the template to clarify this.

There is no FAQ at the moment. Could you start one? I'm sure others and myself who have been involved in the renaissance of the programme would be glad to contribute to it. Geometry guy 13:37, 20 May 2007 (UTC)

Aye cap'n. I can start one. I'll post an announcement here once I have a working version. Silly rabbit 13:59, 20 May 2007 (UTC)

Thanks! It'll definitely be a good thing to have comments from someone not too close to the development of the programme. Meanwhile I've patched up the /Assessment page. Geometry guy 14:27, 20 May 2007 (UTC)

Moving pages with assessment comments

When moving an article, you have to remember to also move the /Comments subpage if it exists. For instance, when Euler integration is moved to Euler method, the talk page Talk:Euler integration automatically goes with it, to Talk:Euler method. However, the subpage Talk:Euler integration/Comments is not automatically moved to Talk:Euler method/Comments; you have to do this by hand.

This is a pity as it will go wrong in the future. Unfortunately, I don't have any better suggestion that just telling everybody to keep this in mind. -- Jitse Niesen (talk) 08:04, 20 May 2007 (UTC)

Maybe a bot could check for this :-) --C S (Talk) 09:40, 20 May 2007 (UTC)

Is this a problem for all articles with archived talk pages as well, eg Talk:Entropy/Archive7 ? If so, this is a much bigger problem, and should be urgently patched in the wiki software. Jheald 10:01, 20 May 2007 (UTC)

Is there an extant proposal to modify Special:Movepage so that it offers an option "[ ] Move subpages (if any)" in addition to "[ ] Move associated talk page(s)"?  --Lambiam^Talk 10:24, 20 May 2007 (UTC)

Thanks for pointing this out Jitse! I agree that it is definitely a flaw in the wiki software, especially now that subpages are encouraged for so many things (e.g., /doc pages for templates). I would also note that if a page about a rated mathematician is moved (e.g. to make the form of the name comply with Wikipedia guidelines), then there may also be a Talk:.../Data subpage to move. Geometry guy 10:40, 20 May 2007 (UTC)

That was me, sorry about that. I moved the page, fixed the redirects, but did not think of the comments page. Good to know in the future. Oleg Alexandrov (talk) 00:59, 21 May 2007 (UTC)

To answer my own question above: yes, there is such a proposal: http://bugzilla.wikimedia.org/show_bug.cgi?id=9626. If you think this is a good idea, you can vote for it.  --Lambiam^Talk 06:31, 21 May 2007 (UTC)

Help required for a big development of Trigonometry and related articles.

The article is somewhat shell-ish; i outlined a framework for the new article on the article talk page. Please, let's get this article good.. i love trig! ♥♥ ΜÏΠЄSΓRΘΠ€ ♥♥ ^{slurp me!} 19:27, 20 May 2007 (UTC)

References

Hey everyone, as you may know Geometry guy and I are working on categorization of the various Math articles. I have noticed in rating my first hundred or so that there seems to be a recurrent lack of references on various articles ranging in class and importance from stub to B and low to high. Is there anything that can be done about this? I for one have about four gigs of electronic mathematics texts and would be willing to upload them to a central location for use by editors. Let me know what your thoughts are on this. Thanks--Cronholm144 04:20, 15 May 2007 (UTC)

Yes, references are important. Google books is an awesome resource for finding references.

There are also a couple of tools which allow one to format references given the ISBN; template builder, and my own tool (the latter is slow and produces code which always needs tweaking, but is useful as a backup). Oleg Alexandrov (talk) 04:28, 15 May 2007 (UTC)

These are all good tools but unfortunately Google doesn't allow for easy reading, I.E. it only shows snippits of the work. The cite tool is good, but If the author doesn't have a usable ref, it won't work quite as well. I just would like for there to be a way for editors to be able to actually cite the material, rather than to just list titles in the bibliography.--Cronholm144 04:55, 15 May 2007 (UTC)

Right, it just offers a few pages. But if you know what you search for, and go through a few books in the list of results (or search through the given book for more pages), you can learn a lot of stuff and is much more efficient than digging through a real book or visiting the library, I think. Oleg Alexandrov (talk) 15:44, 15 May 2007 (UTC)

We do have a project-page devoted to referencing Wikipedia:WikiProject Mathematics/Reference resources. Your electronic text sounds interesting, not being attached to a university put most online journals out of my reach, however I can see problems with copyright and licences if these are put in a public space. --Salix alba (talk) 07:50, 15 May 2007 (UTC)

I have created a page that list the references that I can provide in text form, most are DjVu or PDF. User:Cronholm144/List_of_References Be warned the list is rather extensive. I hope you all take a look. Just E-mail me and I will send you the required material...but only if I know you. My E-mail is in my UBXes under basics. Hope I can be of service!--Cronholm144 06:05, 16 May 2007 (UTC)

P.S. Since I have not posted the texts themselves on an open site I think this is alright... anyone here know copyright law?

I had attempted to do a similar thing [45] but my list was not as comprehensive as yours. It should be easy to source most of our math articles with standard graduate school references. I felt, however, that I was being a little lazy by not tracking down the "best" sources. shotwell 11:45, 19 May 2007 (UTC)

I have revamped the Wikipedia:WikiProject_Mathematics/Reference_resources. I would like some input on how to improve it further.--Cronholm144 04:41, 24 May 2007 (UTC)

Subscripts on underbraces

In Faà di Bruno's formula, I tried to edit this not-too-satisfactory expression:

$n=\underbrace {1+\cdots +1} _{m_{1}\ {\mbox{terms}}}+\underbrace {2+\cdots +2} _{m_{2}\ {\mbox{terms}}}$

In normal LaTeX, as opposed to the somewhat stripped-down version of TeX used on Wikipedia, a subscript on an underbrace would be directly under the center of the underbrace. As a first step toward achieving that result here, I tried something:

$n={{\underbrace {1+\cdots +1} } \atop m_{1}}+\underbrace {2+\cdots +2} _{m_{2}\ {\mbox{terms}}}$

Not surprisingly, the expression with the first underbrace looks OK by itself, but is not correctly aligned with the rest of the expression. One could of course but empty expressions under the other terms, but that seems more cumbersome than what the software ideally would provide for.

Here's the surprise: Look at the SECOND underace in the SECOND display. At least on my browser, it now appears directly under the center of the underbrace, as one would normally wish it to be, even though it code is identical to what appears in the FIRST display. Is the (temporary, at least?) solution just to put some dummy blank expression down there somewhere so that the display has enough room for these to fit down there?

And how 'bout a more permanent solution? I know nothing about who maintains the software or how; I just think of it as if it is inexplicable divine providence. Just file a bug report through the usual channels? Michael Hardy 21:59, 21 May 2007 (UTC)

Perhaps something is temporarily broken, because the example on the formula help page looks to me the way you expect. This may have something to do with a TeX "style" decision. Compare using an explicit "\displaystyle".

$\displaystyle n=\underbrace {1+\cdots +1} _{m_{1}{\text{ terms}}}+\underbrace {2+\cdots +2} _{m_{2}{\text{ terms}}}$

Also note that I use "\text" instead of "\mbox", which fixes another problem not mentioned. --KSmrq^T 22:48, 21 May 2007 (UTC)

Yes, the problem seems to have gone away for me, though the bad images are cached. --KSmrq^T 23:52, 21 May 2007 (UTC)

So next time you encounter this problem, change the TeX in a way that does not change make a difference, e.g., add \, or {} at the end of the equation (the problem was fixed in a software upgrade about half a year ago, but, as KSmrq said, the bad images are cached). -- Jitse Niesen (talk) 01:39, 24 May 2007 (UTC)

An invisible change can be simpler still: add a space (almost anywhere inside the <math> tags).

$n=\underbrace {1+\cdots +1} _{m_{1}\ {\mbox{terms}}}+\underbrace {2+\cdots +2} _{m_{2}\ {\mbox{terms}}}$

$n=\underbrace {1+\cdots +1} _{m_{1}\ {\mbox{terms}}}+\underbrace {2+\cdots +2} _{m_{2}\ {\mbox{terms}}}$

The caching is presumably based on a hash of the characters, with no regard for meaning. Also note that in the above example pair I did nothing to fix the second problem, for those who didn't see it before. --KSmrq^T 23:33, 24 May 2007 (UTC)

Why do they not just modify the caching so that it removes a few of the oldest entries from the cache each day? They would then be re-calculated as if they were new formulas. Then the effects of any software changes would eventually propagate to the entire cache. It seems to be an obvious solution. JRSpriggs 11:03, 25 May 2007 (UTC)

Reliance on information

Perhaps someone might want to suggest changes or join this experiment: User_talk:Edgerck#Reliance_on_Information Comments are welcome (down the page, please!). I hope this is useful. Edgerck 11:03, 22 May 2007 (UTC)

5280 (number)

I nominated this for deletion, at Wikipedia:Articles for deletion/5280 (number). Comments welcome. Oleg Alexandrov (talk) 04:55, 23 May 2007 (UTC)

Should I mention this Afd this to WP numbers? I think it is as much their issue as it is ours.--Cronholm144 05:09, 23 May 2007 (UTC)

AFD

I've nominated List of prime numbers for deletion here. Feel free to comment. —METS501 (talk) 20:21, 24 May 2007 (UTC)

OK, don't feel free to comment any more. :-) Closed as speedy keep. —METS501 (talk) 02:45, 25 May 2007 (UTC)

Yeah. :) Sometimes it helps testing the waters over here before nominating an article for deletion. If mathematicians here say a math article sucks, the rest of the crowd at AfD usually has no choice but to agree. :) Oleg Alexandrov (talk) 03:38, 25 May 2007 (UTC)

...and another

Someone's nominated three coin for deletion: Wikipedia:Articles for deletion/Three coin. Michael Hardy 00:05, 25 May 2007 (UTC)

still another

I have nominated table of divisors and table of prime factors for deletion. --Trovatore 04:16, 25 May 2007 (UTC)

Quintic equation

If anyone has a minute, can they try to decipher this edit and reinsert it in coherent English? It was written by a user who doesn't speak English very well, and has been removed by me for the time being. —METS501 (talk) 18:00, 26 May 2007 (UTC)

Geometry vandalism

I take it the semi-protection of geometry has expired, because we're right back to vandalism. My assessment of the experiment is that vandalism completely disappeared during protection, and positive contributions appeared. Conclusion: semi-protection should be permanent. --KSmrq^T 04:11, 27 May 2007 (UTC)

Yuktibhasa the first treatise on Calculus

In the article Yuktibhasa it is said that the work of the same name by Indian astronomer Jyeshtadeva, is considered to be the first mathematical treatise on calculus. This became a DYK also. Most of the sources online refer to the work thus. However, certain users have questioned this notion in connection with Indian Mathematics and Kerala School of Astronomy and Mathematics. Rather than leaving the resolution to quasi experts, this question should be settled here, I think.

The conversation referred to is ongoing at Talk:Indian mathematics the major players are User:Jagged 85 and User:Fowler&fowler. However most articles that mention the history of calculus will be affected by the result of this conflict.--Cronholm144 07:09, 27 May 2007 (UTC)

Well, as there is no original research allowed, at most certain references may have to be added. It is outside the scope of Wikipedia to rule on what is the first treatise on calculus (even if that is a meaningful statement). Charles Matthews 10:14, 27 May 2007 (UTC)

Portal updates

I'm going to be away from Wikipedia for a few weeks and I haven't had time to update the Mathematics portal. It will go bust next Monday unless someone updates it. Every week the portal looks for a new article of the week at a specific page. These pages need to be written ahead of time. Specifically, someone needs to fill out

• Portal:Mathematics/Featured article/2007 21
• Portal:Mathematics/Featured article/2007 22
• Portal:Mathematics/Featured article/2007 23

You can copy the basic structure from Portal:Mathematics/Featured article/2007 20. Just pick your favorite article and write a short blurb about it. Pictures are good. You can see a list of articles already featured at Portal:Mathematics/Featured article archive. -- Fropuff 07:03, 16 May 2007 (UTC)

Some potential choices, culled from a discussion at the Reference desk proceeding from a request for an interesting math topic for a high-school presentation:

• Pascal's triangle (B?) article is a mess
• Interesting number paradox (stub) Too short
• Fractal (B+) Selected for 21
• Zeno's paradoxes (B+)
• Tic-tac-toe (B)
• Topology (B)
• Cardinal number (B) Difficult to find a good image; Continuum hypothesis used recently.
• Ordinal number (GA)
• p-adic number (B)
• Platonic solid (B+) Used recently
• Minimal surface (stub) Too short
• Monty Hall Problem (FA) but used last year
• Nomogram (start) Too short
• Analog computer (B)
• Map projection (GA) Selected for 22

 --Lambiam^Talk 19:58, 16 May 2007 (UTC)

I've commented on the above. Here also is the list from Portal:Mathematics/Suggestions. Cronholm will be shocked that some of the above have not yet been rated! Geometry guy 11:52, 18 May 2007 (UTC)

• Derivative (GA)
• Nash equilibrium (GA)
• Ordinal number (GA)
• Order theory (GA)
• String theory (GA)
• Sylvester's sequence (GA)
• Znám's problem (GA)

To save this from breaking, I've arbitrarily put Fractal in the next portal. The blurb is just a cut and paste from the introduction, so needs improvement. Geometry guy 12:06, 18 May 2007 (UTC)

The only one that shocked me was Zeno's paradoxes and Platonic solids,the rest I can understand, I have updated the ratings.this is the other Cronholm144--Πρ 03:43, 19 May 2007 (UTC)

Sadly noone improved Fractal or has made any further suggestions. One option is to go for Pascal's triangle next, even though it needs a bit of work. There is a colourful Image:Sierpinski-rgb.png to use as the lead image, connecting fractals and binomial coefficients. Just a thought. Geometry guy 19:41, 22 May 2007 (UTC)

I tried to improve Pascal's triangle, but the closer I looked, the more I found it a confusing mess. I think this one is hopeless for the portal. Most of the other articles above are either too ragged, or don't seem to offer the prospect of a decent image. Map projection might be okay, so I would suggest that. Any comments? Geometry guy 15:32, 23 May 2007 (UTC)

A quick skim of map projection is encouraging; looks like an above average article with a variety of content, broad appeal, and numerous figures and links. The most apparent weakness is that the mathematics does not go very deep. --KSmrq^T 15:19, 24 May 2007 (UTC)

Now copied in... Geometry guy 12:56, 25 May 2007 (UTC)

...but with a link to Fractal, which a user kindly fixed today. Unfortunately it is too much work to bring deep mathematics to the portal, and no one appears to be up for that, so I've found a nice A-class basics article, namely Golden section for number 23. I guess we will just have to ask Fropuff please not to take any more holidays ;) Geometry guy 18:32, 28 May 2007 (UTC)

Liminal property

According to this article, "liminally compact" is another way to say "locally compact". I asked the author of the page two months ago whether some reference could be added (see User talk:Wikimorphism). I got a reply that it was definitely used as claimed in the article, but no references have appeared and the author has vanished. So, is anybody familiar with this usage? -- Jitse Niesen (talk) 12:44, 20 May 2007 (UTC)

Apparently the contributor was not sure it had every appeared in print. The article is only a stub, and a dubious one at that, so it would be no great burden to recreate it should the need arise. I have PRODed it. --KSmrq^T 13:19, 20 May 2007 (UTC)

Uh... I think I made a mistake on this one. :( after the PROD expired I "deleted" the article, but I don't think I have the power to actually delete articles. Could an admin fix my mistake? Thanks--Cronholm144 19:48, 28 May 2007 (UTC)

Bertrand Russell GA/R

I have nominated Bertrand Russell for WP:GA/R due to inadequate referencing. I hope the article gets the attention it deserves during this process to retain its quality rating. Please see discussions at Wikipedia:Good_article_review#Bertrand_Russell. TonyTheTiger (talk/cont/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 16:54, 25 May 2007 (UTC)

The review was speedily closed to delist. CMummert · talk 12:42, 26 May 2007 (UTC)

A speedy delist. That's a new one, isn't it? The usual result of nominating a math-related article for GA/R is argumentation and then delist. But I suppose it's wise of them to skip the usual bickering with folk from here and go ahead to the delisting. --C S (Talk) 13:15, 26 May 2007 (UTC)

I applaud the new procedures. They save time and trouble for everyone. -- Dominus 13:51, 26 May 2007 (UTC)

However, I would suggest a change of name to Wikipedia:Articles with footnotes, since the evident criteria of the project have nothing to do with the quality of the articles. This is of course partly tongue in cheek; but if there is any support here, I will go through with it. Septentrionalis PMAnderson 01:14, 27 May 2007 (UTC)

I have noticed that there is some serious animosity here towards the standards people, along the lines that they insist on irrelevant, perhaps ignorant, and superficial changes to otherwise good articles and refuse to recognize the quality of articles whose referencing does not satisfy their arbitrary but inflexible requirements. I share this frustration regarding good mathematics articles that can never achieve Good status because the needs of mathematics differ from the needs of other, more empirical subjects where frequent, inline referencing is the only means of assessing veracity. However, Bertrand Russell is a biography, and it makes purely factual (as opposed to logical) claims that really should be justified by some reliable source, and in this article, they are not. The same is true of Georg Cantor, mentioned down the page here. Mathematical biographies are not "mathematics", referencing-wise. Just including a (however laudably-complete) list of bibliographic sources is not good enough, since how am I, the reader, to find a particular fact in any of them without any guidance? (See also the video, now on YouTube, of Serre on how not to write mathematics, regarding "citing the collected works of Euler"). Even in mathematics articles, any surprising claim should be cited in one of the sources (a deep theorem, for example); since truth is stranger than fiction, in biographies, all claims are surprising :) Ryan Reich 01:38, 27 May 2007 (UTC)

The gruff way in which these presumably well-meaning people throw their weight around does not help to reduce that animosity, such as speedily delisting an article before even anyone had a chance to realize it had been put up for review. And what can we say about this singularly unhelpful and brusque brush-off in response to a request for clarification about a requirement for a "solid rewrite", since, as far as the WikiProject Mathematics is concerned, it is an A-class article. The response was, literally and in its totality: "If this is the case then the Maths Project needs to reconsider its rating since that is a wholly inaccurate assessment."  --Lambiam^Talk 17:33, 27 May 2007 (UTC)

And there is one major modern biography of Cantor: the one by Dauben (Aczel is a popularization; most of the other book-length works are either dated, or deal with the mathematics.) I would assume, without further checking, that any statement not purely mathematical and not otherwise sourced claims to refer to Dauben, who has an index. Evaluating that claim would involve reading the article alongside Dauben, which I have not done; and which Bad Articles haven't done either..

It would require doing so even if every reference to Dauben were duly footnoted, with almost as much work.

I suppose we should be grateful that juvenile and incompetent editors are engaged in this frivolity, and not doing wider harm to the encyclopedia. Septentrionalis PMAnderson 18:23, 27 May 2007 (UTC)

Re Lambiam's comment: Cantor was one of the articles that was rated A-class before the very new A-class review, so it would have been conceivable that the process wasn't right. I thought that must have been the case until I noticed that the article is also rated A-class by three other wikiprojects including Biography. Nevertheless, the reviewers are probably correct that the article doesn't satisfy WP:WIAGA. People outside this project also grumble about the state of the GA process, but I haven't seen serious discussion towards reworking it from the ground up, which I think is what will be required. CMummert · talk 23:47, 27 May 2007 (UTC)

I think that there exists a powerful feeling within this project is that the GA process is broken and should be ignored, and the in-house ratings of Bplus and A replace it. I have even heard a person here say that they would rather have an article stay start class forever than be reviewed by the GA process. I am actually a fan of the GA process in general and I have participated in listing GA articles in the past, but the process cannot be applied in the same way to mathematics articles. I agree that there should be a discussion of the compatibility of Maths articles and the GA process here, if only to be able to present a united front in the future.

Regarding the Bertrand Russell delist, the article, which has a tag that "consensus was reached" for its delisting, was only a candidate for delist for one hour and nineteen minutes. This does not seem appropriate even for a "speedy" delist. I will end this post with the title of the announcement that Calculus was no-longer a GA class ariticle, "Obscure article Removed Status of Good Article" You can see it in its original context here. I think that this kind of thing illustrates why some of us here are jaded. --Cronholm144 02:49, 28 May 2007 (UTC)

I have recommended that GA be moved, at Wikipedia_talk:Good_articles#Requested_move. If it is, I would be content to ignore it. Septentrionalis PMAnderson 20:50, 28 May 2007 (UTC)

Georg Cantor Good article review

Georg Cantor has been put on Good article review, I suppose, as a punishment for emphasizing his maths over his (non)-Jewishness. Feel free to comment. Arcfrk 07:31, 26 May 2007 (UTC)

No, I recognize the name of the nominator; this is simply more footnote-worship. Septentrionalis PMAnderson 01:06, 27 May 2007 (UTC)

If you have any problems as regards myself PMAnderson please take it to WP:ANI. If you do not, and continue to make remarks on other talk pages as regards myself, I will not hesitate in reporting you there for baiting me. We both disagree on the level of citationing an article needs, so let's leave it at that. LuciferMorgan 22:44, 27 May 2007 (UTC)

I am pleased to come back from ANI bearing news that this threat seems to have been retracted. I admit I do not share LuciferMorgan's simple and unjustified faith in what citation can accomplish; but we also disagree on whether "citationing" is an English participle. Septentrionalis PMAnderson 20:53, 28 May 2007 (UTC)

How many internal links to "mathematics"?

The number of Wikipedia pages linking to mathematics exceeds 10,000 (ten thousand) and I stopped counting at that point.

• Is there a quick way to count them?
• Does that page hold the record, i.e. is it the one with the largest number of such links? (So I suspect.)

Michael Hardy 01:37, 28 May 2007 (UTC)

See Wikipedia talk:WikiProject Mathematics/Archive 25#Most linked to math articles. You could ask Mathbot (i.e. Oleg) for an update of User:Mathbot/Most linked math articles, if you need current information. JRSpriggs 05:39, 28 May 2007 (UTC)

The list is at User:Mathbot/Most_linked_math_articles: I believe this list only counts mathematics articles linking to a given mathematics article. For example, there are about 5500 mathematics articles linking to mathematics (and this is number one by a huge margin). The list is fairly up-to-date, except that since then Cronholm and I have been down the list to about the 800th most linked article adding maths ratings.

Regarding the first question, links to an article can be counted by loading the "What links here" list into AutoWikiBrowser and filtering out the links which are not in the main space. Geometry guy 10:04, 28 May 2007 (UTC)

I count 13642 links; discarding redirect pages, talk pages, and pages in other namespaces, I count 10462 articles linking directly or via a redirect to Mathematics.  --Lambiam^Talk 10:19, 28 May 2007 (UTC)

There is no quick way to count links using the web interface, but there are some programming APIs that can be used. The record for most links used to belong to United States. Right now that article has 301,386 links (counted using m:query.php which I learned has serious performance problems with this sort of query). CMummert · talk 22:43, 28 May 2007 (UTC)

Iteratively Re-weighted Least Squares

Hello to everybody at the Math Wikiproject. While evaluating articles to be created at WP:AFC, I encountered this Wikipedia:Articles_for_creation/Today#Iteratively_Re-weighted_Least_Squares. I am not too good with things math related so can someone here who is more knowledgeable review the submission to see if it is worthy of an article? Thanks for helping. -- _Hdt83 ^Chat 06:52, 28 May 2007 (UTC)

It was created by Salix alba and subsequently edited by Lambiam and myself. In case anyone else here cares to view the results, they are now at iteratively re-weighted least squares. —David Eppstein 19:59, 28 May 2007 (UTC)

External link at Mathematician

I appear to be in conflict with a user who in this edit removed a link I had just added to the article Mathematician. The edit summary is: careercornerstone.org advert link, not a good quality link for this article. This user wrote to me on their talk page: "And yes I am very unflexible about this. When I clean up a mass spamming I expect it to stay cleaned up."

I don't want to get into a revert war, which this would clearly become. I'd appreciate it if some of you could give an independent judgement whether and to what extent this link is (in)appropriate.  --Lambiam^Talk 16:29, 27 May 2007 (UTC)

P.S. I just saw that the AMS has several links to this organization on its website: [46], [47], and [48] (the last two having the very same link that was removed from the external links section at Mathematician). 17:08, 27 May 2007 (UTC)

I'm not sure if it would help to explain that you are not connected with Career Corner, or that you do not intend to mass include the link. I would have some doubts about the link: it is a commercial link, and it offers career advice. Skimming suggests that it is sound; but career advisor is one of the things WP is not. Perhaps wait a week, and then add the first AMS link above (the other two are linkfarms)? Septentrionalis PMAnderson 19:35, 27 May 2007 (UTC)

The organization behind the link is not commercial. It also has good information and seems more informative than the AMS link. The potential problem is that I'd guess there are quite a lot of similar sites and that the addition of one link will lead to many others. So, the question is: Is this one particularly good?

Yes, the user that removed the link is inflexible about it, but in my experience also susceptible to reasoning. -- Jitse Niesen (talk) 20:01, 27 May 2007 (UTC)

Thanks Jitse, I take that as a compliment! (: The story with careercornerstone.org is that it was part of a mass spamming. I only have a problem with that particular link and I am sure that there are plenty of other Mathematician career links it could be replaced with. Even a commercial link would be fine by me. (Requestion 20:54, 27 May 2007 (UTC))

Since I'm visiting this math project I would like to bring up a relevant topic; The mathematics of Wikipedia mass spammings. I'm a spam fighter, I see a lot of Wikipedia spam, and I've noticed something interesting that happens during mass spammings. It doesn't make a difference how blatant or how heinous a mass spamming is. There will always be regular editors who WP:AGF and want to keep the spam. It's a constant and that number works out to be about 3%. So imagine a case where an external link is added to thousands of Wikipedia articles. Most of the spam will get deleted but some will stick and unfortunately the pro-spammers have figured out that this is a successful strategy. I can extrapolate and see an end game where all Wikipedia is consumed by this spam. I see some game theory and some statistics at work here, am I missing any related or important fields? Also from a mathematics perspective is there any advice that you can give me to help deal with this growing problem? (Requestion 20:54, 27 May 2007 (UTC))

What makes a link "spam"? Is it a property of the link, or of the process and external to any intrinsic qualities of the link and is the removal a punitive measure for misbehaviour? Would the AMS put spam links on their own pages, not once but repeatedly? The web site seems pretty good to me (at least in the areas for which I can judge this, which includes mathematics). This may be because they don't need to worry about generating money and are actively supported by many of the leading professional societies (such as the AMS). It also helps that they focus on a limited range of academic disciplines: Science, Technology, Engineering, Mathematics, Computing, and Medicine. As mathematicians we tend to gripe that young people have completely wrong ideas what it means to be a mathematician; well, this website does a decent job of giving the right idea. If other equally good career centre websites exist, I'm not aware of it, and I don't expect a deluge if we open the gates.  --Lambiam^Talk 21:18, 27 May 2007 (UTC)

What is the nature of link spam? That's a complicated question. It's part property, causality, contiguity, and personal identity. Every spamming is different and no one rule applies globally. The intent of removal is more preventive than it is punitive. In fact the whole purpose of the escalating {{spam}} tags and the blacklist is to make the spam stop. Unfortunately spam usually returns and sometimes it even grows as is happening in the Mathematician article. Rewarding it is definitely the wrong course of action. I don't know anything about the AMS links you mention and I have no opinion of them. (Requestion 05:46, 28 May 2007 (UTC))

American Mathematical Society--Cronholm144 06:03, 28 May 2007 (UTC)

What about this rule: if an editor in good standing adds a link, based on their judgement that the link enhances the value of the article, then the mere fact that that link has been used in other edits deemed spamming is not sufficient cause by itself to warrant reversion. Does that sound reasonable?  --Lambiam^Talk 10:04, 28 May 2007 (UTC)

Why would you want to reward spamming behavior like that? Look at this as a complex interconnected dynamical system and think about how a reward plays into the game theory aspects at work. Besides, adding previously deleted spam links just isn't a good idea. Do you really want to fight over a spam link that a different editor in good standing wants to delete? (Requestion 18:41, 28 May 2007 (UTC))

Think of it this way: why would you let spammers control your criteria for what is or is not a good link? Wouldn't it be better to make that determination by judgments of knowledgeable editors, rather than by whether or not some spammer has decided to spam that link? And how do you know, in each case, that the persons responsible for creating the spam are the same as the ones rewarded by the existence of a link? —David Eppstein 18:55, 28 May 2007 (UTC)

It's how WP works, anyway: different opinions in tension. There is a spam blacklist for links. If a link is not blacklisted, adding it is up for grabs. Charles Matthews 18:59, 28 May 2007 (UTC)

Requisition, if there is a non-spam link that contains the same information, by all means replace it. If not, I would hate to remove a useful link just because someone decided to spam it.--Cronholm144 19:34, 28 May 2007 (UTC)

The link wasn't there before they spammed it. (Requestion 19:58, 28 May 2007 (UTC))

I understand. I never meant to imply anything to the contrary, but the link is appropriate for the article--Cronholm144 20:48, 28 May 2007 (UTC)

Fact: spamming works. And consequently it blights our lives. On an individual level, it means we need to use spam filters for our emails (and check their content regularly), while for Wikipedia it means we need to have bots which systematically remove spam, and dedicated users like Requestion who patrol pages for spamming. It is a pain.

But it is worth asking why spam works. In emails, it works because for every 10000 users for whom the spam is an irritation and a violation, there may be one for whom it is just what they were looking for. The same principle applies to Wikipedia. Sometimes a spammer's link is a useful addition to an article. Requestion suggests a figure of 3% for spam links which some other editor accepts. This is surely higher than Wikipedia can tolerate and we should definitely try to bring it down (one editor's acceptance is not enough unless well argued, as it seems to be in this case). However, denying the reason that spam works will have little or no effect in reducing it. Just because a link was not there before it was spammed does not mean it is not a useful link. I hope that in more than 97% of the cases (99.9% might be more appropriate!) the spam link is removed permenantly, but that is not the same as saying that all cleaned up spam links stay cleaned up. Yes, the spammer gets a reward for spamming even if 0.1% of their links survive, but this is not a zero-sum game: as long as knowledgeable and impartial editors decide which 0.1% survives, Wikipedia can benefit too. This is no comfort for the spam fighters, I know, but putting our hands on our eyes and saying "see no evil" does nothing to reduce the evil in the world. Geometry guy 21:13, 28 May 2007 (UTC)

Thank you User:Geometry guy for your analysis. The 3% value I mentioned is my "spam deletion challenge rate" which is how often I get into time consuming arguments about deleted spam. The amount of raw spam that sneaks its way into articles is far higher. (Requestion 14:41, 29 May 2007 (UTC))

I previously wrote a long explanation of the origin of the term "spam", but then deleted it figuring everyone knew. But now it seems people are confusing the different notions of spam, so let me write it again. Spam, in one of its early forms, referred to unsolicited bulk emails (and subsequently other forms of messaging, such as postings to Usenet and instant messages). The key is here "unsolicited" and "bulk". You may get an unsolicited message, but it is not spam if it is not bulk. If one is subscribed to a mailing list, one will get bulk messages, but it cannot be called unsolicited.

What is spam on Wikipedia? "Unsolicited" cannot play a role in the definition, as everyone is invited to contribute to the "the free encyclopedia anyone can edit". By the very nature of Wikipedia, nobody is required to consent with an explicit permission before a link is added to Wikipedia. Rather Wikipedia "spam" only refers to the "bulk" criterion. As mentioned previously, some of us get bulk messages everyday, from various mailing lists. They may not be useful or interesting to us most of the time. But that is how it works; it is the very nature of the medium.

Now let me comment on the "winning" by spammers. We may curse the minority of people that like to get emails about "V I 4 G R 4", shake our heads, and say "the spammers won", but what about a Wikipedia contributor, the majority of whose contributions may be useless or detrimental to Wikipedia? If a few of these contributions are of great value to Wikipedia, and we keep them in Wikipedia, did this contributor "win"? What would happen if we decided to go through Wikipedia, deleting content by figuring out if the majority of contributions by one person are useless? Supposing most of Wikipedia would still be intact (as we can expect) after such an action, was this really a good thing to do? That's what is really the topic under discussion. Let's not confuse it with misleading analogies (cf apples and oranges) perpetuated by usage of similar terminology.

Ultimately, to echo Charles Matthews, unless it's on the spam blacklist, by the nature of Wikipedia, the link is up for discussion. If consensus says keep the link, keep the link. --C S (Talk) 16:33, 29 May 2007 (UTC)

no definition or discussion of "strong"

Hi... hey, if I had a dollar for every instance of the word "strong" in mathematics articles, I'm sure I could buy a tiny microwave from Walmart... but there doesn't seem to be any section of any article that defines/discusses "strong" (I'm told it means "result A is stronger than result B if B can immediately be deduced from A"). This is definitely strongly needed.. need something to wikilink the word "strong" to. I really appreciate your help. Ling.Nut 06:41, 29 May 2007 (UTC)

PS I bet it would be a small, wikilinkable subsection of a larger, more general article.. but I have no idea what article that would be... thanksLing.Nut 06:42, 29 May 2007 (UTC)

You mean like a fortiori? —David Eppstein 06:46, 29 May 2007 (UTC)

Yes I do, in fact. But the link goes to the top of a table... and it's impossible to tell which entry is meant.. say for example "blah blah blah found an even [[a fortiori|stronger]] proof that..." Is there any way to.. umm.. write an article for the term? Or write three sentences to stick in another article? Thanks! Ling.Nut 06:54, 29 May 2007 (UTC)

Maybe wikt:a fortiori is more satisfactory? —David Eppstein 07:00, 29 May 2007 (UTC)

(undent) Well, yeah, sort of. I was really hoping for a very brief discussion of how the term is used in mathematics. But for now, 'tis enough, 'twill serve, and all that... thanks!!! Oh if you ever do write such an article please drop a line to my talk. But I'll use wikt for now. thanks again. Ling.Nut 07:04, 29 May 2007 (UTC)

Would it be satisfactory to include it at the list of words in Mathematical jargon?  --Lambiam^Talk 12:58, 29 May 2007 (UTC)

I've added it there. Ryan Reich 21:44, 29 May 2007 (UTC)

Rn

What is the convention regarding the use of $\mathbb {R} ^{n}$ versus Rⁿ? Jhausauer 20:13, 29 May 2007 (UTC)

See /Archive5#question about formatting of standard symbols (I didn't find a more recent discussion). The project tends not to be prescriptive, but there seems to be a preference for bold inline html, and blackboard bold math in display. Geometry guy 20:31, 29 May 2007 (UTC)

There's another possibility: ℝⁿ (type &Ropf; or copy-and-paste the unicode). It should look more like the math version, but may work less well for people who don't have big unicode font sets installed. —David Eppstein 21:17, 29 May 2007 (UTC)

ℝ? Doesn't seem to work for me. Silly rabbit 21:38, 29 May 2007 (UTC)

Sorry, I didn't look carefully enough at my source. &Ropf; should work in MathML but is unavailable in HTML. Another way of typing the same thing, that does work in HTML: &#8477;. —David Eppstein 21:52, 29 May 2007 (UTC)

This may depend on your OS, browser, monobook.js, installed fonts, and the house Uranus is in, but for me ℝⁿ isn't very legible. ℝⁿ, with the font size one up, is almost twice as tall and quite legible, although the subscript is a bit too low.  --Lambiam^Talk 22:23, 29 May 2007 (UTC)

This is mentioned in the mathematics style manual. We use "'''R'''" inline and "\R" (or equivalent) in displayed TeX equations. --KSmrq^T 05:55, 30 May 2007 (UTC)

Archives of this page

Wikipedia_talk:WikiProject_Mathematics/Archive Index is currently broken. I have fixed the most obvious break, which is that, after number 20, archive titles have a space before the number.

However, more seriously, the complete archive takes many seconds to load and now breaks the infamous pre-expand include limit. (What? Never heard of that? Take a look at Wikipedia:Template limits: this is useful knowledge, since it affects quite a few of our activities.) I propose that the complete archive should be replaced by a pre-2006 archive, and that the years (2006 and 2007) in the table should link to a page listing all the archives for the given year. This would not break the pre-expand include limit. I would just do it, but thought that other editors might like to know that something went wrong. Geometry guy 22:06, 29 May 2007 (UTC)

I've now implemented this. Geometry guy 00:41, 30 May 2007 (UTC)

Thanks for taking care of that. I have never tried looking at the entire archive. CMummert · talk 05:06, 30 May 2007 (UTC)

Neighbourhood (mathematics)

There is a discussion at Talk:Neighbourhood (mathematics)#Which comes first: neighborhood of a point or of a set?, and a few more mathematicians in that neighbourhood would be appreciated. :) Oleg Alexandrov (talk) 05:38, 30 May 2007 (UTC)

Importance of mathematics articles

I promised several visitors to my talk page to initiate a discussion here about importance ratings in the maths rating system, and this seemed an appropriate moment to do so.

Although there are many articles for which the current class grading is wrong (and I have made many such mistakes), it is usually clearly or uncontroversially wrong, and therefore easy to fix. Importance is harder to handle for at least three reasons:

1. lack of clear definitions of what the importance levels mean (in particular, for mathematics articles);
2. lack of guidance on the context within which importance should be assessed;
3. are we rating the importance of the topic or the article?

First, here are the current definitions:

• Top Subject is a must-have for a print encyclopaedia
• High Subject contributes a depth of knowledge
• Mid Subject fills in more minor details
• Low (WP 1.0) Subject is mainly of specialist interest. (WP 1.0 Math) Subject is peripheral knowledge, possibly trivial.

The top and low importance seem to me to be the most problematic. What does "a must-have for a print encyclopedia" mean? Which encyclopedia? EB? An encyclopedia of mathematics? And does "must-have" mean that such encyclopedias have an article on the topic, or that there would be mass protests if the article were removed? As for low importance, is "specialist" the same as "peripheral"? It certainly isn't the same as "trivial". Also there seems to be quite a gap between Low and Mid, which means that Mid is getting overloaded.

A proposal to update the scheme has been made, which seems to be an improvement in some ways, but not in others. For example, it concentrates a lot on whether a topic has achieved local, continental or international notability, which is largely irrelevant for mathematics. Also it seems confused over the second issue above, context.

Consider e.g., motive (algebraic geometry): this is an extremely important topic in modern high-brow algebraic geometry, but within geometry as a whole it is relatively less so. How can we compare it to platonic solid, for example? And within mathematics as a whole it is certainly only of specialist interest, and hence, arguably, peripheral.

So far I have been taking the view that it is more helpful to assess the importance of a topic within its own context, since it is more discriminating. However, I think this needs to be discussed.

Finally, articles vs topic. For articles about mathematical subjects, the distinction is probably rather minor, but for articles about mathematicians, there is another closely related question: are we rating the importance of the mathematician or the article? So far, I believe we have been following the WikiProject Biography guidelines, which suggest the former.

To illustrate the difference, consider Ramanujan. Certainly he was a genius who made remarkable contributions, but his impact on mathematics is not in the same league as Euler or Gauss. Yet an article on Ramanujan is a must-have, not only because of his contributions, but because of the fascinating story, and the deep insights it provides into the mind of a mathematical genius.

I think these issues need to be clarified in a way that makes the importance rating as useful as possible to the Maths Project, and that we really need to have mathematics-specific descriptors. Geometry guy 15:26, 20 May 2007 (UTC)

Overall importance or within context?

I think that we should have relatively few articles of "top" importance (say, 2% = 300 articles within mathematics) and that the majority of articles should be "low" importance. Articles of "top" importance should appeal to non-mathematicians so they can't be about deep concepts; there may be some exceptions like Poincaré conjecture that are important in maths and have hit the headlines in the newspapers. That means that we should be very selective: after 50 or so mathematicians and elementary stuff like square, triangle, addition, there is not much left.

"The importance of a topic within its own context" depends a lot on what you consider to be its own context. The article on pseudo-differentiable quasi-widgets is not that important in the context of mathematics, more important in widget theory, and crucial to the theory of pseudo-differentiable quasi-widgets. I hope that Geometry guy can clarify this point.

As an example, I'll explain the ratings that I have in mind for numerical analysis:

• Top: only numerical analysis itself.
• High: major subfields like optimization, interpolation, root finding, numerical integration; and also the most important methods (I haven't thought this through, but I'm thinking about Gaussian elimination, Newton method, fast Fourier transform, and no others); about a dozen in total.
• The rest to be divided between mid and low.

I haven't rated any of the articles mentioned, except numerical analysis which I upgraded from "high" to "top", so I've no idea what the actual importance ratings are. But I've seen quite a lot of articles being rated, and most importance ratings match with how I'd rate them. -- Jitse Niesen (talk) 13:13, 21 May 2007 (UTC)

This is quite a different view to the one I was trying to express, but I think I agree with some of the points. At the moment there are 135 Top importance articles. About 2200 have been rated so far, and I estimate that there are about 6000 articles worth rating at the moment. So 300 seems to be about the right ballpark, although since Top importance articles are more likely to have been rated already, we are possibly undershooting. I also agree that we should have #{Low} > #{Mid} > #{High} > #{Top}. This is not going to happen with the current definition of "Low", because editors who have worked hard on articles they are interested in are hardly going to call the subject "peripheral". For instance Lazy caterer's sequence is currently rated "High" (see the talk page history). At the moment there are more mid importance articles.

The main point where I disagree with Jitse is on the prioritization of elementary mathematics. I don't think we should be afraid to say, for example, that the Atiyah-Singer index theorem is High importance (possibly even Top). This is partly because I find it unhelpful to think of WP as a single encyclopedia like EB (which is 20 times smaller, with only about 70000 articles on 1/2 million topics) — it is more like a nested family of overlapping encyclopedias. Within our Encyclopedia of Mathematics, there is also an Encyclopedia of Numerical Analysis, and so on.

So I think there is a good case to be made for rating importance within context. When I wrote the above I wasn't sure what this should mean, but following the discussion below, I think context should be interpreted using categories. Thus if Category:pseudo-differentiable quasi-widget contains a large number of varied articles in it (and its subcategories), we can be pretty confident that its lead article is very important! On the other hand if the category doesn't exist, or is rather meagre, then the context for pseudo-differentiable quasi-widgets will be a category like Category:widget theory in which it could be of rather low importance, or it could be one of the major examples.

From this point of view, Optimization (mathematics) is probably Top importance. On the other hand Square (geometry) is probably not. Triangle is also currently rated "High", but "Top" is arguably more appropriate. Addition is, of course, top importance. Geometry guy 16:49, 21 May 2007 (UTC)

Re: This is not going to happen with the current definition of "Low", because editors who have worked hard on articles they are interested in are hardly going to call the subject "peripheral". — there is some of that, I'm sure, but I wonder if there's also a selection effect here: the articles that get enough attention to be rated are also less likely to be on topics of low importance. —David Eppstein 06:46, 28 May 2007 (UTC)

List of fields

I would like to propose expanding the current list of Fields for the rating scheme. Especially if we take up Geometry guy's suggestion to assess importance within its own context, it's crucial to have a proper classification for various contexts (i.e., fields) that can occur. In particular, I strongly believe that Algebraic geometry should be its own field, not part of Geometry and topology. This would greatly alleviate some of the thorny issues mentioned above, not just concerning motives, but pretty much all modern algebraic geometry. Arcfrk 03:14, 21 May 2007 (UTC)

I definitely think we need to re-consider field, problematic articles abound say Talk:Cross product and Talk:Sheaf (mathematics) both have reasons for being in geometry and algebra, the latter could nicely fit in algebraic geometry but the former less so. One possibility is to have allow two fields so you could have field=algebra and field2=geometry. There is also a good case for an algebraic geometry field as there are a large class of articles in this group. There is also the mathematician who could well do with being listed by their field of study as well. The danger with too much expansion is that we end up duplicating the category system.

As to importance, I've always been a fan of the proposal mentioned above as it seem to be a more objective criteria, loosely we could have coverage or scope

• Of high importance across all numerate discipline - everyone should know this
• Of high importance throughout mathematics - all mathematicians should know this
• Of high importance in a major field of mathematics - all those working in the field should know this
• Of importance within one field (high importance in a sub-field) - most working in the field would know this
• Mainly limited to a sub-field
• Specialist, mainly work of one researcher.

Curiously principal component analysis could be applied to this: there are several ways to rate articles: how well known something is, the number of fields/sub-fields its covered by, how useful the result is, when its likely to be taught. These are likely to have a strong level of correlation. Assuming you could give each of these a numeric score, you could put all of these into a big matrix, find the cross correlation matrix and perform SVD to get the largest eigen vector, representing the principal mode of variation. When you get at the end is probably the important score. The task is then to find a set of words which descibes this well. ::--Salix alba (talk) 09:01, 21 May 2007 (UTC)

Look again at sheaves; they are relevant to logic as well as geometry, with topos theory as common ground. In fact, MacLane and Moerdijk have written Sheaves in Geometry and Logic: A First Introduction to Topos Theory (ISBN 978-0-387-97710-2). We lose deeply interesting connections in mathematics when we try to force every topic into exactly one area. As for algebraic geometry, I think it transformed into a rather different field when it refounded itself on schemes, something that can be very confusing for a reader at the level of, say, Bézout's theorem. For example, on page 294 of Hartshorne we find, "In other words, a curve is an integral scheme of dimension 1, proper over k, all of whose local rings are regular." Few of our readers would see it that way! I'm not sure what the implications should be for this discussion, but it should at least caution us that different readers and different editors may frame a subject in radically different ways. --KSmrq^T 09:41, 21 May 2007 (UTC)

Interesting comments! There are certainly problems with the field system — in particular, the fact that only one field can be assigned means that compromises have to be made. However, I have not found this so difficult in practice: for instance Cross product is clearly an article set in the context of elementary Euclidean geometry, even though the same concept could be discussed in a more abstract-algebraic way. I also don't have a problem with the fact that the same subject can seem quite different at different levels of abstraction. For me, sheaves a very geometrical way of looking at things, even logic, but then I would say that ;) — there is certainly a case that they belong in foundations.

I would prefer, as far as possible, to take a pragmatic point of view. I think a field2 would overcomplicate the system. For mathematicians, an alternative would be to use the same trick that has been introduced for historical articles, i.e., replace the mathematician field (which isn't a field anyway) by a mathematician=yes tag.

I agree with Salix alba that we don't want to start duplicating the category system: categories provide plenty of context for importance assessment, and also address some of KSmrq remarks. So I am against expanding the field system to take on this role: it isn't up to the job, it isn't needed, it would be too complicated and too much work.

Pragmatically, fields were introduced to break up the assessed articles into manageable groups. I would therefore propose just to split up fields when they become too large. At the moment algebra and geometry and topology have twice as many entries as any other field, and there is no sign that this trend will change. Myself, I'd prefer to split the latter into geometry and topology, rather than separate out algebraic geometry (partly because of the overlap with number theory and algebra). (In fact, I'd already been planning to do that!)

Any ideas for subdividing algebra? Geometry guy 11:10, 21 May 2007 (UTC)

On the question of field2, there have been a few articles that have crossed my Watchlist recently, where I think there's quite a strong case, eg:

• Talk: Information theory. Currently Applied mathematics. Also Probability and statistics ?
• Talk: Information entropy. Currently Probability and statistics
• Talk: Asymptotic equipartition property. Currently Probability and statistics Applied mathematics.
• Talk: Sigma algebra. Currently Probability and statistics Analysis
• Talk: Spinor. Currently Geometry and topology. Also Mathematical physics ?
• Talk: Spectral theorem. Currently Analysis. Also Algebra ?

... etc.

Bearing in mind that the most important thing is the reverse lookup here -- ie what shape are articles in that are important under Probability and Statistics, under Applied Maths, etc., I think it may be quite valuable for a few articles for their ratings to appear on more than one of the sub-lists.

I also wonder whether it's right that Numerical Methods appear to be by default being filed under Analysis? (eg: Talk: Newton's method) Jheald 15:20, 21 May 2007 (UTC)

Actually it is quite easy to list an article under more than one field because VeblenBot produces the tables using "What links here". All you have to do is link the relevant field page on the article talk page. However, I'm worried that this could be overused, which might reduce some of the benefits of breaking up the articles by approximate field.

For instance, information theory relates to probability, statistics, physics, and applied mathematics, but it may be better to decide on one of them. I'd prefer to go with applied, since it best reflects the variety of applications/influences. Also the applied mathematics field is rather underpopulated, and not yet clearly defined: its meaning is partly going to be determined by which topics we decide it covers. For instance, we may decide that it covers numerical analysis as well. A similar decision (between probability and analysis) could be made for topics in measure theory.

In other cases, the existence of two plausible fields may suggest a need to actually have two articles! I think this is the case for Spectral theorem, and spinor field seems to be a redirect with possibilities! Geometry guy 17:16, 21 May 2007 (UTC)

PS. A lot of these issues will go away if/when Wikipedia:Category_intersection is implemented.

I would suggest pretty much all articles on information theory subjects at least go under Probability and Statistics, because it is very much a statistical idea, dealing with probabilistic quantities; and it is often provides useful ways to think about statistics and statistical questions. It is very much another tool in the statistical armoury. Information theory itself should maybe dually go under Applied mathematics as well, but constituent articles on subjects like Information Entropy, Asymptotic Equipartition Property, Minimum Message Length etc ought primarily to be under Probability & Statistics. Jheald 21:40, 21 May 2007 (UTC)

You may be right, I am no expert, but I am a little wary of the argument that information theory is another tool in the statistical armoury. I can only attempt an analogy: the derivative of a function is very much a geometrical idea, dealing with tangency between a line and a curve, or more generally, tangency of a linear subspace; it is one of the major tools in differential geometry. Does that mean it is most helpful to place Derivative in the geometry field? We have to try and remember that the maths rating field is not a categorization, but an organizational tool. Geometry guy 22:26, 21 May 2007 (UTC)

I am a bit surprised to have encountered such entrenched resistance against introducing Algebraic geometry as a new field for the purposes of the rating project. For once, I would have to regretfully conclude that Geometry guy's argumentation, which is usually a model of clarity, is self-contradictory. If the field Geometry and topology is getting overloaded, then it would seemingly make sense to split off Algebraic geometry, which is uncontroversially a well-defined field of its own, with its peculiar scale of importance. Moreover, he amply illustrates the need to assign the proper context in order to rate the article, so that we do not end up comparing motive (mathematics) with platonic solid (both currently within Geometry and topology). Additional pragmatic advantages would include simplifying the task of raters and making the whole process more objective. In particular,

• it would help editors pick the articles in subjects that they are experts in and in which they can provide a fair rating and, especially, helpful comments for further development;
• for the editors involved in broad rating project across multiple fields, it would streamline the process of assigning the importance by gauging it within the correct field.

Other comments: I quite like Salix alba's definitions of levels of scope/importance, as the ones currently in use really make me scratch my head for nearly every article save the very top importance class, such as Geometry, or clearly technical ones a la Apothem. We just need to come up with descriptive, easily remembered names for his six classes. I also think that to be useful the list of fields should be less precise than the AMS Subject Classification (and of course, the categories system), but agree with Jheald's point that the reverse look up feature makes multiple fields desirable in some instances. As for specific examples of expansion, besides my suggestion of Algebraic geometry above, I think that Numerical methods should not be part of Analysis and (unless it is already covered by Applied mathematics) deserves to be its own field; and Representation theory can be split off Algebra. Arcfrk 00:40, 22 May 2007 (UTC)

I have filed all "numerical analysis" articles under "applied". We should at least be consistent (of course I think that I'm right and that it should go under "applied" instead of "analysis"). -- Jitse Niesen (talk) 01:53, 22 May 2007 (UTC)

I agree and would be happy for us adopt this as a convention, accepting that their can also be a deep analytical compoment in numerical analysis. I would like to adopt a similar convention for information theory. Another issue (which maybe deserves a separate debate) is Galois theory. At present the categories emphasize the algebraic rather than number-theoretic aspects of this, which surprised me. Geometry guy 02:36, 22 May 2007 (UTC)

I only have time to reply briefly to Arcfrk. I'm sorry I was not clear, but I don't think I was being self-contradictory, nor do I see here any entrenched resistence, just a preference, expressed only by me, to split geometry and topology into a geometry field, and a topology field. The problem I have with algebraic geometry as an organizational field (rather than a category) is that it has too many points of view: arithmetic, algebraic, analytic and geometric. The overlap between number theory and algebra is already quite tricky without bringing arithmetic algebraic geometry into the picture. One would also have to decide which parts of commutative algebra are algebraic geometry (well, all of it really, but then I would say that ;) )

However, the main point I was trying to make by comparing motives with platonic solids was not that these are incomparable because one is geometry and the other is algebraic geometry. The same argument would apply to a triangle and an exotic sphere, or to an elliptic curve and a Grothendieck topos. They are incomparable. This is why I believe that context should be provided by categories, not by broad-brush fields. There is no need to reinvent the category system here. Geometry guy 02:36, 22 May 2007 (UTC)

Linking to article hierarchy

I was starting a thread on the same topic as this one but one day later on the wikipedia talk:WikiProject Mathematics/Wikipedia 1.0 page and expressing my viewpoint that the importance assessment should better be done within the context of all of maths. Based on the discussion above, my augmented list of arguments in favour of single maths context for importance is the following:

• Assessment within disciplines would lead to a serious proliferation of Top/High labels; this I think is inevitable unless an unusual number of articles turned out to be more important viewed accross categories/fields/subdisciplines than within them, which I find hard to believe;
• Deciding how finely grained subdisciplines to use adds another layer of complexity; obviously the finer the grid the more Top/High-importance articles; this debate has clearly started on this page;
• Assessment within the totality of maths fits in my mind better with (one of) the goal(s) of the whole grading exercise: prioritising the articles form the viewpoint of importance to a high-quality encyclopaedia.
• The importance rating (or prioritization) accross all of maths is possible if difficult (and sometimes inevitably contested - but so is assessment within fields). It is in fact an execise that editors of paper encyclopaedias have had to do in the past to choose topics for major / minor articles, sections in articles or omission. For Wikipedia, while there is no cap on the number of pages to produce, we have another scarce resource: editors' time. Hence the prioritisation on the level of mathematics still makes sense, at least for as long as we are quite far from having good-quality articles covering all topics which should definately be of Top / High importance within all of maths; and
• As the rating appears on the Maths tab, related to the WikiProject mathematics, it also seems natural to keep the rating on the level of the WikiProject (unless we want to start splitting the project, which probably is not a good idea at this time).

As for how to implement importance assessment on the level of Mathematics, I made the following poropsal that would explicitily link the importance to the hierarchy of mathematics articles:

• The main subdisciplines in maths (plus some selected "general" articles) should receive Top importance (e.g., Number theory, Algebraic topology, Analysis, Integral). These articles could then refer to High-importance articles for further details.
  • (That would partially resolve the issue discussed above wrt Algebraic Geometry — no matter whether one thinks it should be a new "field" in our classification, it definately is a Top-importance article and thus creates an importance sub-hierarchy in this model)
• Second-order subdisciplines within the Top-importance areas as well as the very few most important objects / theorems should have High importance (e.g., Homology and cohomology, Elliptic curve, Harmonic analysis, Fourier transform). These articles could then link to Mid-importance articles for further details.
• Third-order subdisciplines (or theories) within High-importance topics as well as most definitions, theorems etc. that should belong to a good graduate student's general knowledge regardless of own field of speciality could for the Mid-importance layer; and
• The articles of Low importance could be those that would not likely be interesting to people outside of the speciality.

As for the very valid point that several concepts (such as sheaf) may be found at various levels in such a hierarchy (e.g., sheaf on a quite low level in analysis --> microlocal analysis compared to topology), a possible solution would be to choose the highest rating based on the article hierarchy (which in my mind would bring sheaf to High importance under Top-importance article on Topology).

In any case, a more structured hierarchy of articles, starting from ones with wide coverage with limited technicalities and progressing towards more specific and technical articles through links is something I think is needed for maths articles. And indeed, work has clearly started towards that goal on many topics (Integral, Algebraic geometry come to mind as top-level examples). I have been making a plan for algebraic topology articles for such a treatment. It would be great if the importance assessment scheme could support that kind of "global" structuring effort in addition to pointing out articles for "local" improvement.

But however we decide to use the importance scales, I agree with Salix alba that we need clear (and sufficiently verbose) definitions for the importance grades so that everyone can agree on at least the principle if not specific application of them.

Stca74 08:58, 22 May 2007 (UTC)

I replied to the original post here. There are certainly arguments to be made about making assessments all across mathematics rather than within context, or at least partially taking into account how specialized a topic is. However, I think the comparison with a paper encyclopedia is flawed, as I have already mentioned: WP is a very different beast (encyclopedias within encyclopedias). Furthermore, we seem to keep forgetting what importance ratings are for: they are for editors, not readers! They are not there to say "These are the most important articles in mathematics, dear reader, read them first", they are there to say "Hello, editor, I see you are an expert in homotopy algebras and you want to help improve some articles: these are the articles which the project thinks are highest priority". If we rate across mathematics, all homotopy algebra articles will be low importance, which is not terribly useful. Geometry guy 09:37, 22 May 2007 (UTC)

I surely agree that Wikipedia is different from a paper encyclopaedia, and I also quite like Geometry guy's metaphor of nested encyclopeadias. However, there is also the "top-level encyclopaedia" here, the one that this whole project started to build and the one that is being prepared for the v1.0 "fixed" edition. And it is in this context that I have seen the usefulness of the importance gardings: guidance to those who would like to contribute to finishing the "top-level" first. And I agree, this is clearly guidance to editors, not readers (a point on which I do not perceive serious disagreement in the discussion above). On the other hand, providing such "global" guidance certainly does not prevent anyone from contributing to articles of more specialised interest (this is more or less what I've been doing in the few contributions I've managed to make so far...). As for the specific example of homotopy algebra topics, this is how I would see it: Algebraic topology:TOP --> Homotopy theory:HIGH --> Homotopy algebra:MID --> Individual homotopy algebra topics:LOW (unless MID due to specific reasons..). But in the end, whether such grading is seen as useful depends very much on the ultimate goal of the importance ratings — top-down completeness of the general encyclopaedia or guidance to more specific sub-encyclopaedias. Both are valid goals, and in principle we could have parallel ratings for these purposes, but I'd prefer not to complicate the "overhead" associated to project maintenance. Further comments welcome! Stca74 13:00, 22 May 2007 (UTC)

Thanks, I am glad you like my metaphor! I am also grateful to Stca74 for bringing up the v1.0 fixed edition CD: I was about to add a comment on this myself, because I shouldn't go around boldly declaring what the ratings system is for without mentioning its original motivation to produce the v1.0 CD (which is why the assessment project is called Wikipedia 1.0 in the first place)!!

While this is still an important motiviation, the ratings system has clearly grown since then. However, I don't see an incompatibility between rating in context and building WP 1.0. In fact, it seems to me that Wikipedia:Version_1.0_Editorial_Team/Release_Version_Criteria#Importance_of_topic supports the in-context point of view. Specifically, it gives an example of a hierarchy History -> History of Europe -> History of Poland -> Polish kings and queens. and then goes on to say:

An article labeled as "Top-Class" for the subject of history would probably warrant inclusion in V0.5, V1.0 and other releases. A "Top-Class" article for the history of Poland would be a reasonable candidate for inclusion, but most "Top-Class" articles on Polish kings & queens would probably not be included in early releases. Nevertheless such ranking within a subject area is very helpful in deciding which articles are included first as the scope of the Wikipedia 1.0 project expands.

In other words, the kind of downrating by subtopic proposed by Stca74 will happen anyway when articles are selected. I wasn't sure when I first posted this thread, but this seems to make the case for rating in context rather compelling. Geometry guy 13:39, 22 May 2007 (UTC)

Moving forward from here

As the discussion has died down a little, I thought it would be useful to summarise some of the issues with a few comments, and outline some steps forward.

1. There seems to be agreement (or at least no disagreement) that there should be more articles rated as lower importance than higher importance, and in particular that only a few hundred articles (out of several thousand rated articles) should be rated Top importance. This is not going to happen unless some changes are made: at the moment, the Mid category is the most populated.
2. There appears to be some consensus that context should be taken into account when assessing importance, although there are concerns that this might conflict with point 1, and no agreement whether elementary material is intrinsically more important than advanced material. On the other hand, rating importance within context appears to be coherent with the v1.0 fixed edition plans.
3. There has been much less agreement on how and to what extent context should be taken into account, although several suggestions were made.
   1. The field entry in the maths rating should be the context in which importance is assessed (see also point 6 below).
   2. Context should be assessed using the main category to which the article belongs.
   3. Other mechanisms and ratings schemes should be introduced, such as User:Salix Alba's scope.
4. The fields should be clearly defined to help editors to be consistent about which topics are rated under which field. This may involve making conventional choices: for example, topics in Numerical analysis should be rated under applied, even if it is also analysis.
5. Further to this point, some editors suggested that a field2 would be useful. This can also be achieved more informally simply by linking to the relevant field page from the article talk page. However, yours truly cautioned against overuse of this feature as it might defeat part of the purpose of the field entry in the ratings template.
6. In conjunction with 3.1, Arcfrk suggested that the number of fields should be expanded and in particular that algebraic geometry should be a separate field. Certainly the geometry and topology and algebra fields are already too large to be manageable.
7. The question of how to assess importance of articles on mathematicians has not yet been discussed.

In response to this, I have created Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Importance. At present, it mostly consists of material copied from other pages, but the intention is to develop it to provide mathematics specific guidelines which at least address points 1 and 2. I have also created /defn subpages of the field pages to provide descriptors of the fields. These are gathered together at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Fields: please improve and add to these definitions! I hope this will help to address point 4. For point 5, the linking could be tried out with some of the information theory articles, which are the most obvious examples so far where the single field approach is inadequate.

Concerning point 3, I'm not sure it matters too much that there isn't consensus for time being. As long as we agree that some context should be considered when assessing importance, a diversity of opinion on how much is not going to make a huge amount of difference to the way articles get rated. The ratings system, like the rest of Wikipedia is definitely a work in progress, and I would prefer to take a fairly conservative approach to improving it. This partly underlies my view on point 6. Some expansion of the number of fields is going to be needed, and in the long run, I could certainly imagine geometry and topology being replaced by maybe even six fields such as

elementary geometry, differential geometry, algebraic geometry, general topology, differential topology and algebraic topology.

However, doing something like this would require a lot of work, and the case for it is not yet clear, in my opinion. I would prefer to experiment with the geometry/topology split and see what the numbers look like: this would at least make it easier to subdivide geometry later on if this proves necessary.

Finally, apologies to other editors if my over-active participation in this discussion has conveyed the impression of a hidden agenda or a point of view to promote. I initiated the discussion precisely because there were several issues that I was unsure of, and some of these have been greatly clarified thanks to the comments made here so far. However, I freely admit that my developing point of view is also influenced by issues of implementation: any improvement to the rating system needs to have editors willing to do the (often substantial) work required to implement it!

Further comments most welcome either here or on the relevant talk pages in Wikipedia:WikiProject Mathematics/Wikipedia 1.0 (such as the new pages above). Geometry guy 15:40, 25 May 2007 (UTC)

Splitting algebra and geometry

I found about 100 articles in Geometry and topology which are clearly topology, so I guess a geometry/topology split would be about 400/120, which is not ideal. On the other hand, I only found about 70 algebraic geometry articles. Taking algebraic and differential geometry together yields about 190 articles, and the remainder (apart from the topology) is mostly elementary geometry. I would therefore suggest a three-way split into (elementary) geometry, topology and differential and algebraic geometry. The last of these could be split later if necessary.

I haven't yet investigated the Algebra field, but would guess there are quite a lot of linear algebra there. Geometry guy 16:42, 30 May 2007 (UTC)

No there aren't: only about 60 rated linear algebra articles so far. Geometry guy 17:05, 30 May 2007 (UTC)

Sounds fine to me. However, then I would split algebraic geometry from differential geometry right from the beginning. There's been discussion on this in talk:Elliptic curve, and a joint algebraic/differential geometry field would increase the pressure to treat artithmetic issues and geometry in positive characteristics as part of algebra instead, a development that I would find regrettable. However, I could also accept an argument for keeping the current larger geometry and topology field as it is. Even the split of 120 topology, 70 AG and 120 diff. geom. is not that bad, in particular as none of these fields has achieved desired coverage yet. Stca74 17:03, 30 May 2007 (UTC)

I just had a quick look at the exchange and the article itself: it looks like geometry to me, but there is a case for rating it as number theory either instead or in addition. I don't understand the argument for algebra, and the complex analysis point of view on these objects is covered by Riemann surface. I don't see how the split would affect the argument, and of the 190 articles, only about 100 are clearly differential geometry: this is quite a tricky interface to separate. Geometry guy 17:18, 30 May 2007 (UTC)

You're right with the Elliptic curves article. During that exchange I was somehow under the impression that number theory does not have its own "field" either but is currently under algebra. Which is of course not true. Thus even less reason to classify that article under algebra. But back to the topic here: what I'm arguing for is that if we decide to split topology from the current geometry and topology, let's split AG as a separate fied at the same time. The latter are of course connected, but then again so are both to (algebraic) topoogy, and at least I'm not able to argue for any of the links being stronger than the two others. Stca74 19:23, 30 May 2007 (UTC)

Using categories instead of fields

Would it be possible to use categories (which articles already have) instead of making editors choose one field for an article? It would not be particularly difficult to determine which articles are in (subcategories of subcategories of) particular "master" categories. That would make it possible to automatically sort the article into several "fields" and would let us get rid of the field= parameter entirely. That seems better than adding field2= and field3= parameters. Another benefit would be that unrated articles would be automatically detected. CMummert · talk 00:13, 26 May 2007 (UTC)

Some impressions

I have gone over a substantial number of articles in Algebra and Geometry and Topology fields. This is likely to be a contentious issue, but let me say straight away that I have changed quite a few importance ratings, mostly, downrated (explanation below). Here is a rather haphazard list of my impressions from the rating project.

• Vast majority of articles have been filed under the correct field, but there were some (rather obvious) exceptions. I did come across a group of articles which seemed to defy the current classifications scheme, such as Nondeterministic finite state machine, currently under algebra, but in fact, belonging to computer science. Should this be a separate field?

  This issue also caused me some problems. In a sense this material is algebra in the most naive sense of manipulating symbols. However, it is also natural to rate it in the context of discrete mathematics articles. Another case is automatic group: discrete, or algebra? I'm not at all convinced I made the right choice! Geometry guy 20:21, 28 May 2007 (UTC)

• In practice, the category system is not easy to use to gauge the importance, or provide the context. The depths of subcategories vary widely, although the case could be made that this only makes difference for rather unimportant articles. At any rate, I've become convinced that for undeveloped (stub and start class) articles, expertise in the subject is crucial to determine the importance.
• Overall, the importance ratings are inflated, in my opinion. Keeping in mind that one of the main purposes of the rating project is to facilitate the editing, and especially, identifying the 'weak links', this is not terribly important for articles in B-class and above, since they have already received a lot of expert attention. But it may nonetheless be a problem, since there are hundreds of start and stub class articles purporting to be high importance, which ones to edit first?
• Another thing to keep in mind is that the comments are a lot more valuable than the ratings. Thus it may be preferable for experts (and amateurs:-) to spend a bit more time analyzing the articles and reviewing than trying to rate as many articles as possible. There is absolutely no question that the meaningful improvement cannot keep up with the rating process, we simply do not have enough resources.
• This may be worth a separate discussion, but one thing which emerged from looking over a large number of articles is the definite trend to expand articles beyond reasonable length. The rating system has a potential to exacerbate this problem. Some articles on possibly important subjects, but not top level, are reasonably complete; yet they were put into start, or in some cases, even stub class. In my opinion, in most cases it would be unhelpful to expand them further. Yet, somehow I sense a pressure to bring the articles to higher class, which would translate into expansion or inclusion of related material that is already covered elsewhere (and may not belong to the article in question if it is focused enough). I'd be curious to know what other people think about this.
• And, need I point this out, the rating process (especially, importance) tends to be highly subjective, and examples of inconsistencies abound. I was trying to correct them to the best of my abilities, but I apologize in advance to those of you who might feel like your favorite topic got a short shrift! As Cronholm144 writes in comment pages,

Please mail your all complaints to the following P.O. box -- ...I'm kidding! Please add useful comments here. Note: these ratings are not set in stone, please change them as the article progresses.

Arcfrk 12:49, 26 May 2007 (UTC)

I tend to agree with the view that the quality assessment can have an unintended impact on articles, perhaps in particular in maths. It is interesting that the the WP:FACR do not require that even a featured article be necessarily very long. Instead, appropriate length and focus are called for. Still in practice short but otherwise adequate articles do not appear to be even proposed for GA or FA. This suggests that the application of the criteria is being skewed towards too heavy demands. Stca74 13:04, 26 May 2007 (UTC)

(I hadn't seen Stca74's comment)I sense the pressure to bring articles to higher classes as well. I have been responsible for rating a fair number of reasonably complete articles within their respective fields as start class, simply because of their relative length and completeness pales in comparison to the typical B-class articles. This issue has been discussed in the WP 1.0 discussion page if I remember correctly. They proposed that instead of stub, start,..., FA. They (well, someone at their talk page) introduce the idea of completeness of the coverage of the topic as a rating level, there are problems with this system, but it is the most reasonable answer to the problem of completed articles becoming perpetually start class. However the unfortunate consequence of a change of this type would be the necessity to reevaluate a large number of articles...sigh. --Cronholm144 13:08, 26 May 2007 (UTC)

Maybe we need something like "B+ (mini)", "B (mini)", "Start (mini)" would be appropriate ratings for articles which are substantially all that is needed, and wholly adequate, yet only a few paragraphs long. Jheald 23:44, 26 May 2007 (UTC)

P.S. I changed that humourous comment(cited by Arcfrk) into two different "templates." I find the lack of references the most common flaw in most math articles #1. If I don't have anything interesting to say #2. If there are other problems I just type something to that effect.

• needs refs, try finding some [[Wikipedia:WikiProject_Mathematics/References|here]].--~~~~

'''Note:''' These ratings are not set in stone, please change them as the article progresses.

• Please add useful comments here--~~~~

'''Note:''' These ratings are not set in stone, please change them as the article progresses.

I have adjusted the maths ratings template so that it includes part of this last line. For technical reasons (aka the "pre-expand include limit") the total number of kilobytes of comments needs to be controlled, and so boilerplate comments are best absorbed into the template. Feel free to edit my version of this comment at Template:Maths rating. Geometry guy 22:15, 28 May 2007 (UTC)

I noticed and have gone through and edited myself to reflect this change. I am about through the start and stub class articles--Cronholm144 22:20, 28 May 2007 (UTC)

I had thought previously that quality (class) gradings were more straightforward than importance ratings, but a number of issues have come up, and it indeed seems to merit separate discussion, as User:Arcfrk suggests. I agree that the system at present can encourage the expansion of articles for which expansion is either undesirable, not needed, or a low priority. I also agree that a case can be made for promoting some short Stub/Start class articles to Start/B. However, I would caution against the idea of grading a short but "reasonably complete" article too highly. In my view, it is our conception of the meaning of the class grading that needs tweaking. Such a short article should certainly hope for a B or Bplus class grading, but we need to provide space and encouragement for an article to achieve its potential.

It is surprising how much one can do to improve an article. I recently participated in the FAC for Equipartition theorem. There is no reason why this subject in particular needs such a detailed treatment, cf. Virial theorem, which hasn't had the same attention (currently rated Start by Physics, but I think it is B). To me, this illustrates what can be done to lift a short B-class article to FA, and also the fact that a B-class article can be totally respectable.

I think a lot of the problem is the wording of the class descriptors. These tend to assume that an article starts off with an ill-informed description, and is gradually improved as more expertise is brought to bear. This isn't what actually happens for many of our articles. Instead they start as a technically correct definition, which is improved to a technically solid article by expert editors. However, these articles are incomprehensible to most readers, as well as being imperfectly presented or badly sourced. But the class descriptors don't pick this out: they should be encouraging us to maximise the accessibility of our articles.

I suspect this underlies some of our problems with Good Article review, because a technically excellent B article has a big leap to make to satisfy the GA crowd. I think instead we need to encourage the improvement of technically good (i.e., "reasonable complete") articles (with examples, explanations, references) in a step-by-step process, and this applies equally to articles which are short or long. I therefore think we should adapt the descriptions of the classes to our needs, rather than create new classes for short articles. Geometry guy 23:05, 28 May 2007 (UTC)

Article assessment

In a discussion elsewhere, I presented criteria by which I personally judge an article:

---

I would ask of an article:

1. Is it correct?
2. Is it reasonably complete and balanced?
3. Is it clear?
4. Is it compelling?
5. Is it reasonably accessible, given the topic?
6. Is it written grammatically, with correct spelling, and with good typesetting?
7. Is it appropriately illustrated, if applicable?
8. Is it well linked?
9. Is it helpful in providing references and additional resources?

These kinds of questions will be familiar to anyone who has written and reviewed for a journal.

---

The criteria are ordered roughly according to importance, and attempt to be roughly independent. Presented here for your consideration, and possible comment.

I believe I would find it more helpful to have articles given explicit ratings (yes/no/partial would suffice) against each criterion: I could assign ratings more easily, and target improvements better. Also, it would help us edit to explicit shared standards. Might this go in WP:MSM or WP:WPMER? --KSmrq^T 08:13, 30 May 2007 (UTC)

I think this is a well thought out list of criteria for the Mathematics project articles. I have a couple of small grumbles: no.4 seems too high on importance scale (if needed at all for mathematics articles); no.6 is a classical Liar paradox type of sentence (better: is it grammatically correct? or is the grammar correct?). I would also separate the grammar and typesetting, and add another item, my Achilles' heel, is it written in idiomatically correct English? Would it be possible to make a template with these or similar criteria, and add it to subpages of the mathematics articles being rated, much in the same way as 'Comment' subpages were implemented? Arcfrk 08:36, 30 May 2007 (UTC)

P.S. Also, in view of earlier discussion about length and completeness, one might add Is it focused? to the top of the list. Arcfrk 08:48, 30 May 2007 (UTC)

I think that an important point is the overall structure. Does the article naturally flow from the start to the end, or does it jump all over the place? I feel that this is related to KSmrq's compelling (though I'm not sure what KSmrq means) and Arcfrk's focused, so perhaps these should all be combined in one point.

Considering the comments I made when rating articles, I think that I use these criteria implicitly (after all, they're pretty natural criteria, though it's not so easy to formulate them). Many articles failed point 2 (completeness). I can see why making it explicit would be helpful, but it's also more work. -- Jitse Niesen (talk) 19:19, 30 May 2007 (UTC)

Multivariable calculus

Multivariable calculus is in need of some serious expansion. I started to make some changes. Please review my work and expand/correct it. Jhausauer 21:25, 30 May 2007 (UTC)

Normal set

I've prodded normal set, which I don't think is terminology with any particular currency, but if anyone here knows of it being used, please weigh in. --Trovatore 21:30, 30 May 2007 (UTC)

Good articles

Problems with Good article review have generated much discussion recently (see e.g. Wikipedia talk:Good articles) and I have been attempting to encourage the GA process to reform. There are many ways in which it could be reformed, from name changes to clarity over criteria, to more lightweight procedures. Please read the discussions and comment. My current feeling is that if reform is not forthcoming, we should withdraw our support for WP:GA, and encourage the rest of Wikipedia 1.0 (in which we are a leading project) to do likewise: at present, the GA process does not fit into any coherent assessment scheme, since it concentrates too much on citation issues rather than overall article quality. Geometry guy 00:01, 30 May 2007 (UTC)

I believe Good article review should rename themselves to Wikipedia:WikiProject Article Style and Form; that way, they could rate and rank articles as they wish, lessening the insult to those who write articles with A-class content and B-class style. linas 05:12, 30 May 2007 (UTC)

I have attempted to insert a caveat at Template:Grading scheme and have been continually reverted by one Revert Warrior, despite the evidence of our long conversation that there is no agreement where GA fits in that scale, or that it should. See Template_talk:Grading_scheme#Good_Articles. Septentrionalis PMAnderson 15:20, 1 June 2007 (UTC)

I suspect it is unlikely that such a caveat will be widely accepted across Wikipedia, since in non-scientific areas, GA seems to work somewhat better than it does for us. However, we could certainly add such a caveat to our own table (although I would be against making it strongly-worded, or open to criticism as a political statement). I also hesitate, for the time being, to propose removing GA from our grading scheme (I think there may well be maths editors who like to have it there, and value the green cross seal of approval from outside of the project).

However, I would like to propose a more cosmetic change: merging the B+ and GA ratings. This would amount to the following: replace the horrible lime green colour of B+ by the darker green of GA; ask VeblenBot nicely to count and list B+ and GA articles together; and adjust some of the wording in our grading scheme to reflect the merger.

It might also be worthwhile making the B+ grading more robust, and ensuring that B+ articles are properly sourced, but according to the standards of this project, not the inline citation police. In that way GA becomes "B+ with added footnotes". Comments? Geometry guy 17:04, 1 June 2007 (UTC)

Citations for definitions of basic mathematical concepts

At WikiProject Chemistry, we have recently established a workgroup to improve linking to the many (6540...) definitions contained in the IUPAC Compendium of Chemical Terminology. However, we have noticed that one or two of these definitions are not really chemical terminology at all, but mathematical concepts, e.g. bimodal distribution, probability. The chemical usage of these terms is no different from the usage in other sciences, so it would seem misleading to cite a specifically "chemical" reference for the definition. What would you suggest as a good reference for mathematical definiions? Encyclopedia of Mathematics? Thanks for any advice! Physchim62 (talk) 10:16, 29 May 2007 (UTC)

I'm not sure if it applies, but there is Wikipedia:Scientific citation guidelines#Summary style. In brief, you don't always need to give a citation above and beyond the main article you link to. Bimodal distribution and probability seem to be two cases where no citation should be needed. Wikipedia already has those articles, so a wikilink should be enough (IMO). Of course, Wikipedia doesn't have mathematics articles on everything, even everything which could conceivably be interesting to a chemist. For more exotic definitions, you probably won't find them in the Springer Encyclopedia either. Silly rabbit 12:02, 29 May 2007 (UTC)

If a mathematical concept is not specific to a branch of science but important enough for a definition of it to be included in the Compendium of Chemical Terminology, then we probably should have an article on it. Should you encounter such concepts that can't be wikilinked to for lack of an article, please let us know.  --Lambiam^Talk 13:04, 29 May 2007 (UTC)

A point well worth making! Silly rabbit 13:14, 29 May 2007 (UTC)

No problem with that! I've done a quick (and necessarily incomplete) check and and I haven't found any redlinks on mathematical terms. The problems are:

• Referencing: I don't think that "summary style" guidelines apply to these articles in the sense that Silly rabbit describes. Bimodal distribution has a well-defined, technical meaning, and we should reference that meaning if we can (IMHO). See chemical reaction, for example.
• Imaginary unit: I just found this one on my quick check. Chemists (and physicists, I believe) are supposed to use upright type for i, as it is not a measurable quantity. In effect, it might be the same rule which requires upright type for (capital) Σ and Π as operators in equations, although chemists often use italics for other operators, e.g. H for the hamiltonian operator, C_n for the n-fold rotation operator (quick redlink warning!).

Thanks for your comments, Physchim62 (talk) 13:29, 29 May 2007 (UTC)

Our article on the bimodal distribution most certainly needs a reference; I think that Silly rabbit misunderstood you. I am not so fond of using another encyclopaedia as a reference, but it's better than none at all. Apart from that, the Springer Encyclopaedia of Mathematics is reliable in my experience. I had a look at your workgroup page and I saw that I don't need to warn you that you need to actually check the article against the reference. Finally, using upright or italics for i is the mathematical equivalent of the British/American English conflict in Wikipedia: lots of discussion, no agreement, in the end we agreed to disagree. -- Jitse Niesen (talk) 18:08, 29 May 2007 (UTC)

I took the following list of redlinks from a seperate database, that of the "Green Book", but if interested editors would like to create the necessary articles or redirects (probably mostly redirects), obviously this would help clueless chemists! Physchim62 (talk) 13:57, 29 May 2007 (UTC)

• fundamental translation vector
• n-fold rotation operator

-> Rotational_symmetry#n-fold_rotational_symmetry -- Jheald 00:35, 30 May 2007 (UTC)

• base of natural logaritms
• identity symmetry operator

-> identity function -- Jheald 00:32, 30 May 2007 (UTC)

• space-fixed inversion

ie ? reflection in a line, plane, or hypersurface -- Jheald 00:32, 30 May 2007 (UTC)

• inversion operator

-> inversion in a point -- Jheald 00:32, 30 May 2007 (UTC)

• rotation-reflection operator

-> improper rotation -- Jheald 00:32, 30 May 2007 (UTC)

• displacement vector

-> displacement (vector) Needs cleanup -- Jheald 00:32, 30 May 2007 (UTC)

-> or possibly "displacement vector" as a common name for "electric field times dielectric constant". See Electric displacement field and also displacement current, which I think is what happens when you put a dielectric into a capacitor, or something like that.linas 04:55, 30 May 2007 (UTC)

• product sign
• summation sign
• plane angle

I filled in a couple, but it is not clear precisely what the remainder refer to, since no articles link to them, so I can't see how they are used in context. Geometry guy 15:59, 29 May 2007 (UTC)

Above, "base of natural logaritms" should be "base of natural logarithms". Some occur in the Gold Book list (for example plane angle, although without definition). The Green Book mentioned above gives some context; for example "fundamental translation vector" is used in the context of crystal lattices and undoubtedly means the translation vectors that generate the edges of the parallelepiped that is the fundamental region of the lattice.  --Lambiam^Talk 22:11, 29 May 2007 (UTC)

These mostly look like symmetry operators related to crystallographic groups, heavily used particularly in quantum chemistry, to discuss the symmetry groups of molecules (see: Molecular symmetry), and hence of molcular orbitals for quantum mechanical electrons (and also perturbations of them). See also Euclidean group, Point group, Point groups in two dimensions, Point groups in three dimensions, Crystallographic point group, Plane symmetry for WP articles in this area. Jheald 00:32, 30 May 2007 (UTC)

There seem to be several articles dealing with the same point symmetries and symmetry point groups here. Scope for consolidation/cross referencing ? Jheald 00:49, 30 May 2007 (UTC)

Agree. The (remaining) operators are used in the discussion of molecular symmetry, which has a fairly wide range of uses in chemistry. Fundamental translation vector is undoubted related to translation (geometry), although I'm not 100% sure what is "fundamental" about it: it may simply be a synonym for unit cell vector (crystallographic usage), I shall try to check. Physchim62 (talk) 09:26, 30 May 2007 (UTC)

I filled in three more of the redlinks. Can someone finish off? Geometry guy 18:04, 2 June 2007 (UTC)

Set theory category

Should Category:Set theory be a subcategory of Category:Mathematical logic? It seems to be regarded as a subfield by modern set theorists, but I'm not sure if this is the right criterion for populating categories with subcategories, and wonder if it would not be more helpful to have separate categories with many common subcategories. I've been discussing this with Trovatore, but I think a wider discussion is needed. Geometry guy 13:13, 30 May 2007 (UTC)

But perhaps also a subcat of general topology, which is historically what it set out to be? linas 13:34, 30 May 2007 (UTC)

Since there is no requirement that the category graph has to be a tree, the set theory category can be put into several parent categories. Personally, as a logician, I would find it very surprising if it were not in the mathematical logic category.

I think the difficulty is that there are two different meanings of "mathematical logic" in use. To researchers, it means essentially "recursion theory, proof theory, set theory, and model theory". To nonlogicians, it means something like "the logical methods used in mathematics, and the study of those logical methods." It's natural enough for nonlogicians with this viewpoint to think set theory, which has a subject of its own like algebra does, is not part of "mathematical logic" and that the logicians are trying to claim it somehow, but that isn't the historical development.

I disgree with Linas' comment - from my viewpoint the development of set theory was either contemporary with or (more likely) predated that of general topology by a few years. It is true that the phrase "set theory" had a very broad meaning in the early 20th century, but the content of topology has never included things such as models of set theory. CMummert · talk 14:03, 30 May 2007 (UTC)

I also disagree with Linas's comment. However, I'm not convinced that it is sensible to structure the category based on the logician's viewpoint (see below, and also the comments I made on Trovatore's talk page, linked above). I understand that there is a huge overlap, and it is perfectly reasonable to regard set theory as a subfield of mathematical logic: I am not complaining that logicians are trying to "claim" set theory, only suggesting that this might not be the best way to structure the category. As for the historical development, was Cantor's set theory really part of mathematical logic? Additionally, a large part of set theory, indeed the part familiar to most readers (Category:Basic concepts in set theory), doesn't have much to do with mathematical logic at all. Geometry guy 14:59, 30 May 2007 (UTC)

I don't see a problem with having Category:Set theory as a subcategory of Category:Mathematical logic in addition to possibly other categories. After all, the category system operates as a tool for browsing topics, and for such a purpose it does not need to be a tree — a more general directed graph should work fine (prefereably without loops...). A related question that may have been discussed before is whether the maths article classification system should follow the AMS scheme [49]. It is well established and works fairly alright. And by the way, as the habit of having multiple secondary classifications for most articles and books shows, binning of maths topics in a perfectly clean way is quite difficult. Stca74 14:18, 30 May 2007 (UTC)

Indeed, the category graph is not a tree, and there is no reason for it to be. In fact it is rather a long way from being a tree. The concern I have is that if specialist fields express their broadest scope in the category system, then everything will end up being a subcategory of everything else, and the category system will be useless. It seems to me that set theory is so basic, that it should be directly a subcategory of Category:Mathematics. However, in the AMS scheme, it is a subcategory of Category:Mathematical logic and foundations, and that would be an alternative way to proceed. Geometry guy 14:59, 30 May 2007 (UTC)

AMS classification has different aims from WP categorisation. I'm happy with the current position: almost all of the articles within Category:Set theory are logical in interest. There is Category:Descriptive set theory, which in the old days (pre-1920 say) would have been co-extensive with Category:General topology ('sets of points'); but again almost all the content is logic. It has Category:Sets of real numbers in it, e.g. for Cantor set, which is a subcategory also of Category:Real numbers. There might be room for more connections made with Category:Discrete mathematics. Otherwise it all seems fine. Charles Matthews 15:07, 30 May 2007 (UTC)

I wouldn't necessarily be against renaming category:mathematical logic to category:mathematical logic and foundations. I kind of think the top-level subcats of category:mathematics should be fewer. The standard division I'm used to has four subfields, namely algebra, analysis, geometry/topology, and logic/foundations. I think that might be a decent place to start, although I have to admit that I don't know where to put number theory in that scheme. --Trovatore 18:31, 30 May 2007 (UTC)

I also think it might be worth reproducing here a point I made on my talk page: mathematical logic, as the term is used today, doesn't really have much to do with logic in the sense of "the science of making valid inferences". It's entrenched historical terminology (perhaps the only truly enduring legacy of the discredited Russell–Frege logicist school), and it no longer really matters much whether it makes sense or not in terms of its component words. I think maybe this confusion explains how G-guy can say that the topics in the "basic concepts in set theory" cat don't have much to do with mathematical logic, when to my eye they obviously do. --Trovatore 18:41, 30 May 2007 (UTC)

In related news, I have spent a while cleaning up Category:Mathematical logic by subcategorizing a lot of articles. I have also nominated Category:Computation for deletion here. That only sounds odd until you actually look at the category. CMummert · talk 18:50, 30 May 2007 (UTC)

The renaming is definitely one way forward. I agree with Charles, however, that WP categorisation has different aims than traditional or modern mathematics subject classification, and we shouldn't confuse the two. The current top-level subcats of Category:Mathematics are

arithmetic, algebra, mathematical analysis, geometry, number theory, topology, category theory, mathematical logic, discrete mathematics, applied mathematics, mathematical physics, probability and statistics, functions and mappings, numbers, sequences and equations

and several subcategories that are not related to topics in math. Some of these categories reflect what is important to WP readers, rather than mathematicians, and I think it should stay that way. It would then seem natural to include set theory in this top level for the same reason. It is the eye of the reader, not the mathematical logician which matters.

Alternatively Category:Mathematical logic and foundations could be refined into Category:Mathematical logic and Category:Mathematics foundations with set theory as a subcat of both. The two terms are closely related but have a different emphasis (rather like geometry and topology). For instance, Trovatore has suggested that Category:Category theory should be a subcategory of Category:Mathematical logic. I would be uncomfortable with that, as only a small part of category theory (e.g. topos theory) is mathematical logic. On the other hand, it fits comfortably as a subcategory of Category:Mathematics foundations. Geometry guy 19:17, 30 May 2007 (UTC)

I would be strongly against distinguishing "math logic" from "foundations". In practice the terms are synonymous. Which term a person chooses to use sometimes tells you a bit about his philosophical views (though not in any reliable way); it tells you virtually nothing about the content he's discussing. I think all of category theory is math logic; see my remarks above about "math logic" not having much in particular to do with "logic" in the broader sense. --Trovatore 20:12, 30 May 2007 (UTC)

They may be synonymous to the experts, but they aren't to non-experts. One can declare an equality math logic = foundations, but this does not address the fact that these concepts convey different meanings to the general reader (even the general mathematician). In particular, I fail to see how the really important modern subject of higher category theory can be called mathematical logic. Similarly, regarding homological algebra and universal algebra as part of mathematical logic seems odd, whereas it does not seem so unreasonable to regard them as part of foundations (as well as algebraic topology and algebra respectively), because these ideas are used in many branches of mathematics. Geometry guy 22:58, 30 May 2007 (UTC)

I don't really know much about "higher" category theory, so I couldn't say. The basic arrow-chasing that appears in, say, Lang's Algebra, seems to me clearly to have the character of mathematical logic. But if categorists don't think so, I'm happy to defer to them on that point. (Are there any categorists in the project? I don't know of any.)

That would make Category:Homological algebra a subcategory of mathematical logic as well. Just because X "has the character of" Y does not mean X should be a subcat of Y. Geometry guy 10:15, 31 May 2007 (UTC)

G-guy, please do not respond in-line to something in the middle of a comment; you lose attribution and sometimes break the flow of someone else's argument. Homological algebra does not strike me as having the character of mathematical logic. Category theory in general does. But I won't press the point on category theory, because I really haven't usually seen it classified as math logic. --Trovatore 16:34, 31 May 2007 (UTC)

Apologies — I had just returned from some discussions where this was the norm rather than the exception, and had no intention to cause any annoyance or break up the flow. I hope in this case the indentation makes the attribution clear at least. Apologies again, Geometry guy 17:33, 31 May 2007 (UTC)

I think we should be using the standard terminology of the field, whether it's intuitive or not. I'm the first to say that calling these fields "logic" is based on a historical error, but I don't much care; it's a typical fact about language that errors eventually become correct if they're used enough. "Foundations" has its own baggage -- first, it suggests you believe in foundationalism, which you might not, and when it is used distinctively based on content, it often connotes foundational philosophy, which does not seem to be what we're talking about. And there isn't, to my knowledge, any third choice to describe these fields that seem to have a common character.

So as I say, I'm OK with renaming the cat to category:mathematical logic and foundations, but I would oppose any proposal to break that down into "logic" and "foundations" subcats. --Trovatore 01:17, 31 May 2007 (UTC)

I just wanted to clarify that my suggesion was not to introduce two subcategories of Category:Mathematical logic and foundations, but to replace this by two subcategories of Category:mathematics which could lead the reader into foundations/math logic issues in two different ways. However, if this does not find any support here, I have no intention to pursue it. I'm just trying to raise the issue. Geometry guy 18:22, 31 May 2007 (UTC)

Discussion on Trovatore's talk page prompted me to read Wikipedia's guidelines on categories, namely WP:CAT. Particularly interesting is the very first one, which states:

1. Categories are mainly used to browse through similar articles. Make decisions about the structure of categories and subcategories that make it easy for users to browse through similar articles.

From the discussion so far (with the exception of the comment of User:Charles Matthews) it would seem that this guideline instead states:

1. Categories are mainly used to organize the hierarchy of knowledge. Make decisions about the structure of categories and subcategories in accordance with the general practice of experts in the field.

It doesn't say that! Geometry guy 10:15, 31 May 2007 (UTC)

Well, at the very least, I think our categorizations should not be at cross purposes with the standard terminology of the field. That would be endlessly disruptive, as authors applied categories to articles in standard ways, and as knowledgable readers were led astray.

Distinguishing "math logic" from "foundations of math" just isn't going to work; there is no standard distinction between them (except, again, insofar as "foundations" means "philosophy", which isn't what you want) and the categories will be endlessly muddled. --Trovatore 16:34, 31 May 2007 (UTC)

I agree: if WP categorization is at cross purposes to established hierarchies, it will confuse both readers and editors. Geometry guy 17:33, 31 May 2007 (UTC)

Well, this is turning into a general discussion, it seems. Category:Categorical logic should be a subcategory of both Category:Category theory and Category:Mathematical logic. There are good reasons why we can't intersect categories; do this instead. I see no point in Category:Mathematical logic and foundations: verbose and probably hendiadys. I think few top-level subcategories in Category:Mathematics is not going to be helpful. Charles Matthews 21:12, 31 May 2007 (UTC)

Thanks, Charles, I learned a new word :-). Yes, hendiadys is exactly right. I don't see that as a fatal problem, though, if it makes people happier to use the lengthier name. But my personal preference is for the shorter name, partly because the longer one would provide a constant temptation to break it into "logic" and "foundations" subcats. --Trovatore 21:24, 31 May 2007 (UTC)

Re Charles' comment: yes Category:Categorical logic (and also Category:Topos theory) are, and should be, subcats both of mathematical logic and category theory.

I have a proposal to make, which I should have thought of and tried out sooner: make Category:Set theory a subcat of both Category:Mathematics and Category:Mathematical logic. This is justified because:

1. it is a branch of mathematical logic, particularly in expert usuage;
2. like Category:Functions and mappings it concerns a broad and basic topic in mathematics for the general reader, and deserves to appear at the top-level, along with categories such as Category:Arithmetic and Category:Topology.

How does that sound? Geometry guy 10:30, 1 June 2007 (UTC)

This appears to be uncontentious, so I will go ahead. Geometry guy 18:02, 2 June 2007 (UTC)

Why is it called biproduct?

Please see "Why is it called biproduct?" section in Talk:Biproduct. --Acepectif 20:31, 31 May 2007 (UTC)

Because it's both a product (category theory) and a coproduct. Silly rabbit 20:46, 31 May 2007 (UTC)

It's a dessert topping and a floor wax? Jheald 06:46, 2 June 2007 (UTC)

disastrous article

The article titled additional logarithm topics bears certain resemblances to New Orleans three days after Katrina. Probablly some of its material should get merged into existing articles or perhaps new articles on disparate topics. Michael Hardy 21:07, 23 May 2007 (UTC)

I think that's too generous. All the "derivations" are textbook stuff that doesn't belong here at all (I'm not saying that proofs don't belong here; I'm just saying that the theorems proved on that page are not given in any context other than that of an indiscriminate, textbook-like list, and so don't contribute to acceptable content). The "using logarithms" section is really just some competition problems that constitutes a "how-to" guide, and so should go. The continued fractions bit at the end is just an explication of a well-known algorithm for computing continued fractions that is actually given on the page for that topic. This article looks like it was written by a high-school junior taking precalculus. Ryan Reich 21:39, 23 May 2007 (UTC)

I've proposed the article for deletion. If anyone disagrees, feel free to remove the deletion template. Ed H | talk 01:10, 29 May 2007 (UTC)

Well, now we can forget about that disaster. Ed H | talk 02:51, 4 June 2007 (UTC)

Jun 2007

Topologists, help wanted at neighbourhood (mathematics)

Sorry to bring this up again, but two of us disagree rather strongly on whether one should define first the neighbourhood of a point, or the neighbourhood of a set, with no compromise in sight.

While the issue may be trivial, the concept of neighbourhood is important enough in mathematics, that perhaps more people should get involved. The discussion is at Talk:Neighbourhood (mathematics)#Which comes first: neighborhood of a point or of a set?. Thanks. Oleg Alexandrov (talk) 01:46, 1 June 2007 (UTC)

Orphan talk page

Why does Template talk:Numerical algorithms exist when its template does not? JRSpriggs 08:18, 1 June 2007 (UTC)

Admin error! I have fixed it. There is an archived discussion concerning the former template here. Physchim62 (talk) 08:55, 1 June 2007 (UTC)

Sorry, I forgot to delete it. Oleg Alexandrov (talk) 15:39, 1 June 2007 (UTC)

JRSpriggs probably knows about this already, but for those who don't: you can use {{db-talk}} to tag a talk page whose main article is deleted, to have the talk page deleted as well. There is a list of these templates at Template:Deletiontools. CMummert · talk 16:31, 1 June 2007 (UTC)

Thanks to Physchim62 for fixing the problem. Thanks to CMummert for the pointer to Deletiontools; I was not aware of it. However, I probably would not have used the "db-talk" template in this case because I had forgotten that the template was deleted (not paying enough attention); so I did not know why the talk page was there without a template. I do not necessarily think that leaving the talk page for a little while after the article is gone is a bad idea, but there should be some indication on it of what happened to the article and that the talk page will be deleted eventually. JRSpriggs 07:22, 2 June 2007 (UTC)

There's always admin discretion to leave a talk page when the main article has been deleted, but usually such situations are simple errors (admins are only human, after all!). Thanks for bringing it to people's attention. Physchim62 (talk) 12:50, 2 June 2007 (UTC)

Zero

I have been going through the Z articles, and I have found quite a few stubs in the zero section, Zero_ideal, Zero_set, Zero_tensor, Zerosumfree_monoid, Zero_matrix, Zero_module, Zero_order. Is there any way we can unify these articles in a meaningful way. As it stands I don't see these articles growing all that much. Perhaps we could create something along the lines of the List of prime numbers article. Maybe "List of mathematics terms that include zero".--Cronholm144 05:50, 2 June 2007 (UTC)

I will take the silence as a "go for it C" and create something in my sandbox :) --Cronholm144 18:15, 2 June 2007 (UTC)

Zero set clearly has potential to be expanded into a solid article; Zero order may have as well, and I would give Zerosumfree monoid the chance to flourish or perish on its own merits (a redirect might be more appropriate). The other four articles are all zero elements/objects in one way or another, and there isn't much one can say about them individually. There may indeed be scope here for a list, or other unifying article, on such zero objects: in which case, "go for it C"!

Done List_of_zero_terms with redirects in place. I didn't redirect Zero matirx, just relisted it. Now all of the horribly weak stubs can grow together in one place. Feel free to move the page to a better name, just be sure to warn me so I can reset the redirects to the appropriate locations--Cronholm144 18:46, 2 June 2007 (UTC)

BibTex for Wikipedia?

It often happens to me that I want to include a reference to, say, Hartshorne's book "Algebraic Geometry". It is somewhat annoying to always look for it at some page where the reference already is. Is this only a problem / issue of mine or do also other people wish there would be a BibTex-like system on Wikipedia? In the simplest case it would be a page including references to (at least) major math books. It might look like

Robin Hartshorne (1997). Algebraic Geometry. Springer-Verlag. ISBN 0-387-90244-9.	{{cite book | author = [[Robin Hartshorne]] | year = 1997 | title = [[Hartshorne%27s_Algebraic_Geometry|Algebraic Geometry]] | publisher = [[Springer Science+Business Media|Springer-Verlag]] | id = ISBN 0-387-90244-9 }}

Jakob.scholbach 17:35, 30 May 2007 (UTC)

PS. Of course, much more helpful would be a mechanism generating the above reference by something like {{cite book | id = Hartshorne_AG }} . Jakob.scholbach 17:47, 30 May 2007 (UTC)

If you have the ISBN, you can use the Wikipedia template filling tool referenced at Wikipedia:WikiProject_Mathematics/Reference resources#Citation templates. For ISBN 0-387-90244-9 it produces {{cite book |author=Robin Hartshorne |title=Algebraic geometry |publisher=Springer-Verlag |location=Berlin |year=1977 |pages= |isbn=0-387-90244-9 |oclc= |doi=}}, which displays as:

Robin Hartshorne (1977). Algebraic geometry. Berlin: Springer-Verlag. ISBN 0-387-90244-9.

 --Lambiam^Talk 20:41, 30 May 2007 (UTC)

If Wikipedia as a whole does not keep a database, at least WikiProject Mathematics could. (I note with interest that another — more focused — wiki has adopted a scheme of giving each citation its own page.) It would be very nice to have a list, for several reasons.

1. citation data would be easier to find
2. corrections and additions could benefit everyone
3. conventions and standards might be easier

I have proposed this in the past, but encountered an apparent lack of enthusiasm. Also, what is involved in creating and maintaining the data, can we do better than cut-and-paste to use it, and who will do the work? --KSmrq^T 04:09, 1 June 2007 (UTC)

It is not hard to parse all the math articles and extract all citations in a list. I don't know if it is worth the trouble though, the Wikipedia template filling tool mentioned above does a decent job I think. Oleg Alexandrov (talk) 04:12, 1 June 2007 (UTC)

The template filling tool is nice to have in our arsenal, but is rather limited. First, it requires an ISBN for a book, and does not accept ISBN-13. So I tried it on a real example, ISBN 0-875-48170-1, and got the following

{{cite book
|author=David Eugene Smith, Yoshio Mikami, 
|title=History of Japanese Mathematics
|publisher=Open Court Publishing Co ,U.S
|location=
|year=
|pages=
|isbn=0-875-48170-1
|oclc=
|doi=
}}

• David Eugene Smith, Yoshio Mikami,. History of Japanese Mathematics. Open Court Publishing Co ,U.S. ISBN 0-875-48170-1.{{cite book}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)

I deliberately used an improperly hyphenated ISBN (it should be ISBN 0-87548-170-1), and got the same back. The citation I had actually used in the article splits the two authors, splits first and last names for both, links the first author, provides a URL to an on-line copy of the work, links the publisher, provides a correctly hyphenated ISBN-13, and supports automatic linking from a Harvard-style reference in the text.

{{citation
| last1=Smith
| first1=David Eugene
| author1-link=David Eugene Smith
| last2=Mikami
| first2=Yoshio
| pages=pp. 130–132
| title=A history of Japanese mathematics
| place=Chicago
| publisher=[[Open Court Publishing Company|Open Court Publishing]]
| year=1914
| ISBN=978-0-87548-170-8
| url=http://www.archive.org/details/historyofjapanes00smituoft
}}

• Smith, David Eugene; Mikami, Yoshio (1914), A history of Japanese mathematics, Chicago: Open Court Publishing, pp. pp. 130–132, ISBN 978-0-87548-170-8 {{citation}}: |pages= has extra text (help)

There is a substantial difference in favor of the latter. And how am I supposed to come up with the following (from the same article)?

{{citation
 | last =Laczkovich
 | first =Miklós
 | author-link =Miklós Laczkovich
 | title =Equidecomposability and discrepancy: A solution to Tarski's circle squaring problem
 | journal =Journal für die reine und angewandte Mathematik ([[Crelle's Journal|Crelle’s Journal]])
 | volume =404
 | pages =77–117
 | year =1990
 | url= http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D262326
 | id ={{ISSN|0075-4102}}<!--MR 91b:51034-->
}}

• Laczkovich, Miklós (1990), "Equidecomposability and discrepancy: A solution to Tarski's circle squaring problem", Journal für die reine und angewandte Mathematik (Crelle’s Journal), 404: 77–117, ISSN 0075-4102

No ISBN applies, and I have no ID number; and even if I did, the tool will not provide that marvelous URL. --KSmrq^T 05:26, 1 June 2007 (UTC)

I think it could be useful. I have a file with half a dozen of references I use quite often. Something similar is at User:Shotwell/Standard references. I'm not so sure whether it's worth the effort for journal articles, but who knows. We can always set something up and see whether people will use it. It would be nice if we could use it in a more intelligent way than copy-paste, but I'm not sure that's possible. I would however be against extracting all the citations from articles; by doing it by hand we have some quality control. -- Jitse Niesen (talk) 15:37, 1 June 2007 (UTC)

Bear in mind that each editor should cite the particular version of a source they used: so if you have a different edition of a book from another editor, you should use a citation for that edition (with the ISBN from your copy of the book) rather than just reusing the other editor's citation unmodified. This is less of an issue for journal articles (in that fewer have such multiple versions), but citations of those are also likely to be less widely reused.

Another question with reusable citations: when should links to authors (or journals, etc.) be included in them? Policy on links would suggest that a particular author should be linked just once in the references for an article; reuse would suggest that the citation shouldn't depend on the article it's being used in, so all or none (with a given author) should link to the author. Joseph Myers 18:36, 1 June 2007 (UTC)

So, I understand that there is some interest in a Wikiproject-wide list of references. I'm willing to put some effort into it, but I don't know the inner mechanisms of Wikipedia. Is it possible to create and maintain etc. a database inside Wikipedia? Otherwise I would volunteer to set up some reference database outside WP which can be edited by everybody. A mere list of references is a nice thing, but is still kind of a hassle to manually look for the item one needs, especially when the lists grows bigger and bigger as everybody adds his favourite references. It is probably also unefficient because everytime the whole list has to be saved when someone adds a new entry. The advantage, pointed out by KMSrq, of including an URL is definitely something we should not miss, because giving an URL is (at least for me personally) practically more important than the volume no. and the journal's name, at least until one is actually writing a paper and needs the paper-reference, but then good old BibTex does the job anyway. Besides the URL of the paper or book (if there is one) it would also be nice to allow the URL of a review, for example like on MathScinet. Concerning Joseph's remarks: different editions of a book are no particular problem, I guess, they should just be listed as different database entries. Whether to give a wikilink to the author's page or not might be decided by the user by checking or unchecking some checkbox "wikilink the author(s)" etc. Jakob.scholbach 17:30, 3 June 2007 (UTC)

New month, new collaboration

Hey everyone, It's June first and you know what that means... A new Mathematics Collaboration of the Month! The victor, by an overwhelming margin of 3 votes, is Integral. Everyone here should be able to contribute on this one (no excuses this time!). With a little polish and elbow grease, this article will be at A class in no time at all. See you there--Cronholm144 06:21, 1 June 2007 (UTC)

I am not in the habit of participating in these events; few are. However, I'd like to put in a special request for "integral". If this esteemed assemblage of editors could just briefly stop by the page and skim it (it's quite short), then leave feeling embarrassed at the poor state of such a key article, that would be progress. If you feel like a minor edit, or perhaps an observation on the talk page, that would be better still.

Unlike Cronholm144, I've been around long enough to know that topics like this (as described below) are a huge challenge. It is a gateway topic, visible to far more readers than an expert topic like Poincaré duality. It is one of the deepest topics in mathematics, with massive amounts of material to tap. Many editors will have encountered integrals in a simplistic way, and think they know more than they really do. And the topic can be introduced and organized in many ways, with each editor drawing on different taste and training. It scares me.

That said, integral is so weak that even a little effort could make a visible difference.

So, please, take a few minutes of your time and have a look, and perhaps give it a nudge towards improvement. Thanks. --KSmrq^T 07:03, 3 June 2007 (UTC)

I'd like to reiterate my suggestions for facilitating the collaboration by proceeding in phases:

• Phase 1 is like a peer review, in which we identify what the problems with the current version are.
• Phase 2 is a discussion phase in which we reach consensus on the target: what are (and what are not) problems and what to do about them.
• Phase 3 is implementing this.

 --Lambiam^Talk 08:21, 3 June 2007 (UTC)

Flagged revisions (stable versions)

There is a proposed policy at Wikipedia:Flagged revisions about stable versions. The idea is that some pages would be "flagged" and then the flagged version would be shown by default to users who aren't logged in. This has obvious implications for vandalism fighting and quality control.

This has been in development for years, but now the code is apparently finished modulo final approval. Although it is still not certain that flagged versions will be enabled on en.wikipedia.org, the proposal is an attempt to determine some community consensus on the issue. — Carl (CBM · talk) 17:40, 3 June 2007 (UTC)

ratings

User:Geometry guy is perhaps the most prolific assigner of "ratings" on math article talk pages. He ranke deformation theory as of "mid" importance and degrees of freedom (statistics) as low.

Is there some standard according to which that is not idiotic? (I'd have said "low" for the former and "high" for the latter. And "high" for any other topic that, like this one, is covered every statistics course from kindergarten through Ph.D.-level.)

Has anyone attempted to codify standards for these ratings? Michael Hardy 22:35, 1 June 2007 (UTC)

OK, at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Assessment it says "low" means "Subject is peripheral knowledge, possibly trivial." By that standard, ranking degrees of freedom (statistics) as "low" is profoundly illiterate. Nothing kinder can be said about it. Michael Hardy 22:38, 1 June 2007 (UTC)

I have occasionally come across ratings I didn't agree with, and adjusted them accordingly. For example (if I recall correctly), measure theory and harmonic analysis were also low. Real analysis and complex analysis were mid (should have been top). And so on. It might do to cruise through the ratings from time to time and see if there are any eyesores. I think that, rather than a codified standard, it seems to be a free-for-all in which the ratings reach a sort of equilibrium value. During some discussion, unrelated to the present one, G.Guy brought up an analogy with simulated annealing, which seems to be apt for the rating system as a whole.

By the way, I have been assigned the task of putting together an FAQ on the subject of ratings. So far, I've completely procrastinated, but now might be a good time to get it up and running. Silly rabbit 22:44, 1 June 2007 (UTC)

OK, here's a counterexample, Michael. I'm going to say something kinder about it. Geometry guy is working very hard to provide a summary page where the rest of us can consult ratings vs. importance, grouped by broad subject areas. I think he's doing a great job, that everybody is human, that mistakes are inevitable, and that we will foster a better spirit of community by helping each other out than by spewing venom on this talk page.

At least I think that's a counterexample. I might be wrong, though – I've been characterized as a troglodyte in this venue before today, and I suppose it may happen again.  ;^> DavidCBryant 22:55, 1 June 2007 (UTC)

Hello all, thank you for your comments. I am attempting to do two things simultaneously right now. The first is to make up for the patchy coverage of the maths rating scheme by attaching maths ratings to approximately 1/3 of the 15000 articles in the List of mathematics articles. The second is to try and refine and understand what importance ratings are for, and how to assess them. These two processes feed into each other.

Importance ratings are always going to be subjective and will fluctuate, but the goal of the second task is to reduce this subjectivity and fluctuation. In the meantime, however, the first task is flawed in many ways: first, I (and others who join me in this effort) will make subjective judgements; second, we will make mistakes; third, the criteria on which these judgements are made have not yet been fully elucidated. I can only ask others to have patience, and also bear in mind that this is a wiki: anyone can fix or update a maths rating. I am saddened by how the harder I work, the more complaints I receive on my talk page. No one needs to complain: just fix the rating.

Importance seems to cause more trouble than anything else. I am beginning to wonder if it should be renamed "priority" (which is the term used by some other WikiProjects): it is not about how important a subject is, but how high a priority it is for us to have a good article on the subject (in the context of related articles.) This does not mean that there will be fewer mistakes, only (I hope) that editors will be less upset by them. Anyway, I think that the word "priority" should at least be mentioned much more in our assessment pages. Recent experiences only serve to reinforce my opinion that the terms "peripheral" and "trivial" should be eliminated as soon as possible from the summary of the low-priority rating. (These words are not actually part of the WP 1.0 scheme, which uses the term "specialist" instead, although this is problematic as well.) I will try to fix this tomorrow.

In the meantime, bear in mind that there is a lower importance rating than "low": unrated. If you know an article which has not been rated which you think should be, please rate it. So far, I have got as far as Dei, so if your favourite article comes before this in the alphabet, don't come to my talk page to complain: assess it! Best wishes to all... Geometry guy 00:09, 2 June 2007 (UTC)

I agree with DavidCBryant that Geometry guy is making substantial contributions. When I was saying nothing kinder could be said I was speaking ONLY of that one rating of that one article.

I suspect Geometry guy is seriously confused about the content of statistics, and maybe also about its importance. Michael Hardy 00:37, 2 June 2007 (UTC)

Sadly very few statistics articles have been given maths ratings so far: the subject really needs a champion to go through and assess them. The maths ratings project has been active for quite some time now (at least six months), but even a month ago, there were only 29 assessed probability and statistics articles; now there are 147. This five-fold increase is largely a result of my efforts: I hope this shows I am aware of the importance of statistics, even if I am confused by its content!

As I mentioned above, there is a lower importance/priority rating than "low", which is "unrated" (the bottom 2/3rds, in my view). I've had to skip over many stats articles for lack of expertise: if I were a statistician, I would be more up-in-arms for the stats article that remain unrated than for the ones whose rating is wrong. The ones to which I have added a rating are the ones I thought desperately needed to be put "on the map" for others to rate more accurately.

Anyway, in case it is any reassurance, most of the articles I am skipping over right now, with no rating, are obscure irregular polygons (sometimes in five dimensional space!). You wouldn't believe just how much of this kind of stuff there is! Geometry guy 01:05, 2 June 2007 (UTC)

I strongly believe that comments above involving the word 'idiotic' should be retracted. I would like to express support and highly praise Geometry guy for undertaking an incredibly difficult task of rating broad swaths of articles (literally, thousands). In addition to that, he and others have written rather extensively on the criteria used in ratings on this talk page, although some of the discussion is now archived. It was no sneaky action on his part, as one might erroneously infer from Michael Hardy's comment in the beginning. The unfortunate part is that we did not reach a consensus on what terms should be used for rating importance, and did not establish the clear criteria to be used (of course, individual application of any criteria will always remain subjective). In my opinion, this happened not because of any deep disagreement (indeed, most of the proposals were very close), but due to the general lack of interest to codifying the results of the discussion. As a consequence, there are now multiple attempts to adjust the ratings based on a whole slew of criteria, from the discredited and obsolete four levels to multiple interpretations of the alternative schemes that were discussed, and additionally, the adjustments that are not based on anything save highly opinionated personal choices. I feel that it's TOP PRIORITY to establish at least a draft of reasonable rating scheme that can be used as a reference.

Mid for Deformation theory is correct, in my opinion. I am not a statistitian, but in my classes from kindergarten through the university level, degrees of freedom (statistics) did not establish notability on a par with Euclidean geometry, Fractal, or Riemann sphere, to quote the first three high importance rated articles in the field of geometry. The article itself does not make for an easy determination of the importance (regardless of how you might define importance). As I have pointed out earlier in a discussion of ratings, it is difficult to rate undeveloped (start/stub class) or messy aricles in context and especially for a non-expert. Subjective judgements and even mistakes are inevitable, and we would all benefit from restraint in descriptions of others' contributions, be they posted on this page, talk pages, or as summary of edits. In this I wholeheartedly agree with DavidCBryant's comment above.

Let me repeat some earlier remarks that we should keep in mind one of the main goals of the rating enterprise: to facilitate improvement of mathematics part of Wikipedia, by identifying the key areas needing improvement and matching limited editing resources with a multitude of articles that compete for our attention. It is emphatically not an endorsement of the absolute importance of the subject of the article for mathematics as a whole, or our beloved special area! Having said this, I'd like to point out the fairly broad agreement in previous discussions that only a few articles be rated top importance and relative limited numbered high importance. I mention this, because Silly rabbit has increased importance ratings in many cases that were a lot less compelling than Real analysis, creating an impression that any important topic he would like to put into top and high classes. Hopefully, the newest Geometry guy's thoughts on the rating scheme can serve as a basis of a good rating scheme that we can all agree upon. Arcfrk 01:19, 2 June 2007 (UTC)

Has there been some discussion on my recent upgrades that I was unaware of Arcfrk? The only case anyone bothered to bring to my attention was image (mathematics), which I promptly downrated from high to mid, favoring the isomorphism theorem for high instead. This, I hope, is significant enough that we can all agree belongs in high. Similar upgrades to asymptotic analysis, character theory, representation theory. I didn't think these would be at all controversial, but since it's clear you don't want other editors adjusting the ratings, I'll refrain. I'll just revert my ratings and let someone else handle it. BTW: Maybe you could write the FAQ, too. Silly rabbit 01:50, 2 June 2007 (UTC)

I am grateful to all for both supportive and critical comments. I would emphasise that anyone can adjust ratings. It can be a thankless task sometimes, but please don't be discouraged by disagreement! I have been trying to build on the discussions held here previously to improve the importance page and hence provide better guidance for these ratings, but it is still work in progress. I am acutely aware that this is a high priority, and I will try and push it forward later today. Geometry guy 02:13, 2 June 2007 (UTC)

I expect the importance of an article to be highly correlated with the number of articles linking to it (not counting "List of ..." articles and redirect or disambiguation pages). For Deformation theory I count 17 linking articles, and for Degrees of freedom (statistics) 41. Is it possible to collect this information automatically, for a sanity check of already rated articles and also for checking if some important articles failed to get an importance rating?  --Lambiam^Talk 08:39, 3 June 2007 (UTC)

I see such a list exists already: User:Mathbot/Most linked math articles.  --Lambiam^Talk 08:44, 3 June 2007 (UTC)

One of the approaches taken by Cronholm and me for adding maths ratings (following Oleg's suggestion) is to go down this list from the top. However, the correlation of this statistic with importance/priority is not entirely reliable for several reasons. First it tends to overrate articles of a more general rather than specialist nature. Second, it can be inflated by links between similar articles: see for instance the articles on polyhedra and tilings. Third it tends to underrate articles in poorly developed areas of the maths project, which are often the areas which most need our support and further development.

Furthermore, I strongly believe that articles should be assessed in the context of related articles. It doesn't make a lot of sense to compare Deformation theory and Degrees of freedom (statistics). The former seems firmly Mid to me, in comparison with related articles. I clearly slipped up rating the latter as Low, as it is certainly in the Mid-High range, not because it is "more important than deformation theory", but in the context of other statistics topics. Geometry guy 13:42, 3 June 2007 (UTC)

One difficulty with statistics is that coverage is feeble by comparison to most math topics. One can readily imagine 30 or 40 articles in a list of topics related to degrees of freedom in statistics, but they're not there. Similarly analysis of variance is a vast topic on which one could write several thick volumes, but the article is pretty stubby. Michael Hardy 01:06, 4 June 2007 (UTC)

Help with article in "unconventional computation"

The article Non Universality in Computation has come to my attention. While the papers by Selim Akl that it cites don't appear to be completely incorrect, they are not actually reflective of classical computability theory because they place restrictions on the models of computation that are not permitted in the standard theory of computability. In particular, the papers assume some sort of time scale such that "computers" must complete calculations in a certain number of steps, which is incompatible with the standard definitions.

So while the articles are not completely incorrect, some of the claims that Akl makes are not correct, or overstated at least, and these claims are repeated in the WP article. The claims were also added to the Turing machine article, but someone else removed them.

I think that there is a place on WP for this information, once it has been rephrased to use standard terminology. But the article as it stands is likely to leave readers with false impressions.

I have asked the author of the WP article, User:Ewakened, to comment here, and I would appreciate hearing other opinions on the matter. CMummert · talk 23:12, 29 May 2007 (UTC)

The first cited paper by Aki (that the article is based on) seems to argue quite reasonably that the standard model of computability is not adequate. But there are some unfortunate confusing statements in the introduction that sound like they try to provide a counterexample to universality (in the classical sense) of the Turing machine. This is what went into the WP article. It becomes clearer later on in the paper that the author understands universality differently and basically searches for its meaning by a series of examples. In my opinion, not notable. Jmath666 07:36, 4 June 2007 (UTC)

Name change: CMummert → CBM

My username was recently changed from CMummert to CBM (log). This change will be seen in page histories and your watchlist, if my user pages are on it. — Carl (CBM · talk) 14:32, 4 June 2007 (UTC)

Normal set on AfD

Prod had expired; de-prodded. --Trovatore 03:54, 5 June 2007 (UTC)

Cofactor expansion

After viewing the Determinant article I was surprised to see that cofactor expansion (obviously one method for determining the determinant of a square matrix) doesn't have an article nor does it even serve as a redirect. I thought that I should bring it to the attention of the Wikiproject.--Jersey Devil 20:28, 2 June 2007 (UTC)

I guess I'll eat the bullet on this one. I'll create the stub tonight.--Cronholm144 07:34, 3 June 2007 (UTC)

P.S. In my sandbox, I hate to put unfinished work onto the mainspace.

I'm puzzled; is there something we want to say about cofactor expansion that does not belong in the determinant article? --KSmrq^T 11:26, 3 June 2007 (UTC)

Me too ;) Is this really the same KSmrq who recently said to me "For those of us using popups, articles with definitions — even brief ones — are appreciated." ? :) Geometry guy 13:58, 3 June 2007 (UTC)

Yes, and I'm being consistent. For a definition only relevant in one place, it's better to include the definition in that article. For an extreme example, look at eigenvalue and eigenvector. --KSmrq^T 18:50, 3 June 2007 (UTC)

A redirect #REDIRECT [[Determinant]] ought to have been fine here. The problem is that the Determinant article uses the term, but fails to explain it; and neither does our article Minor (linear algebra), which defines "cofactor" but not "cofactor expansion". The article in statu nascendi at User:Cronholm144/Cofactor expansion should perhaps more properly be called "Cofactor (mathematics)" and could, in finished form, replace the current redirect page of that name (now redirecting to Minor (linear algebra)), with Cofactor expansion being a redirect to Cofactor (mathematics). However, I wonder if it is not better to merge the sandbox article into the existing Minor (linear algebra) article.  --Lambiam^Talk 14:18, 3 June 2007 (UTC)

Midway through the writing I realized the same thing and changed my article's focus to the general cofactor. I am still writing. I think I will withhold my own judgment on the merge (which is valid, but the articles have different aims at the moment) until I finish. --Cronholm144 14:40, 3 June 2007 (UTC)

Is the Cofactor expansion not the same thing as the Laplace expansion ? Jheald 15:29, 3 June 2007 (UTC)

It certainly appears to be doesn't it. :) It certainly looks like there are going to be an interesting set of mergers once I get done. As it stands now I think the redirect for C exp. should definitely go to L exp.--Cronholm144 15:49, 3 June 2007 (UTC)

Well, considering none of us thought to look for it under Laplace expansion, maybe the redirect would be better Laplace exp -> Cofactor exp. But yes, it looks like this whole group of articles could use some merging/refactoring, so it's a good thing you're on the case. Jheald 16:02, 3 June 2007 (UTC)

And we did not read through to the end, because Laplace expansion is mentioned there, and explained as well. It is stated to be efficient for small n. All methods are efficient for small n, but isn't it rather very inefficient for large n? Or is there some clever trick to obtain the cofactor expansion in substantially fewer than n! operations?  --Lambiam^Talk 16:38, 3 June 2007 (UTC)

If you read even further down, at Determinant#Algorithmic implementation, you'll learn the answer ;) However, I think that it doesn't happen that often in practice that you want to compute the determinant of a large matrix. -- Jitse Niesen (talk) 19:15, 3 June 2007 (UTC)

I know that the "obvious" way of using Laplace expansion to compute determinants, computing the determinants of the minors recursively with the same method, requires on the order of n! steps (obviously). I also know that there are more efficient methods that do not use Laplace expansion. Using the "naive" method of Laplace expansion, in total floor((e−1)n!) times a determinant is computed, one for the whole matrix, the others for minors, minors of minors, and so on. However, there are only 4ⁿ square sub-matrices, a number that is soon dwarfed by n! as n grows, so an awful lot of these minors get their determinants recomputed quite often. My question was, in essence, whether some clever way (other than dumb memoization) is known for organizing the computations in such a way that these recomputations are avoided. This question, which is not answered in the article, is more theoretical than practical; but, presumably, the same method could then be used for speeding up the computation of permanents.  --Lambiam^Talk 20:16, 3 June 2007 (UTC)

Have any of you heard of Lewis Carroll's method of matrix condensation? It was a rather interesting read, but I believe it partially bypassed the problems presented by large n, but I can't quite remember. aha! found it mid-write mathworld. The original article is available in JSTOR's catalouge, only six pages and a delightful read. --Cronholm¹⁴⁴ 20:36, 3 June 2007 (UTC)

It's discussed in Volume 2 of The Art of Computer Programming. I can look it up if you don't have a copy handy. Silly rabbit 20:19, 3 June 2007 (UTC)

Oops... I think it must be in one of the new installments. Here is Knuth's paper on it. Silly rabbit 20:29, 3 June 2007 (UTC)

Thanks, you beat me to it (edit conflict) BTW since I am on an algebra writing kick... How does Methods for computing determinants sound?--Cronholm¹⁴⁴ 20:36, 3 June 2007 (UTC)

There's also a related technique, due to Edgar Bareis (?), using Sylvester's identity. I believe this is optimal for large n. Silly rabbit 20:21, 3 June 2007 (UTC)

..and modular methods for integer determinants using the Chinese remainder theorem, implemented for instance in Victor Shoup's Number Theory Library. Which, I think, work better particularly in parallel processing environments. Yes, a new article seems to be called for. Silly rabbit 20:43, 3 June 2007 (UTC)

I am surprised that no one mentioned Gaussian elimination (and related methods, such as QR decomposition) yet! Surely, these are more efficient than any expansion tricks, giving O(n³) complexity for computing the n by n determinant straight away. As far as I can remember, nothing like that exists for computation of permanents. This provides a philosophical 'explanation' why cofactor expansion, condensation, etc that apply equally to determinants and permanents cannot be (even close to) optimal in the determinant case.

Concerning Lewis Carrol method: besides in-house Dodgson condensation, see Bressoud's book referenced in Alternating sign matrix. Arcfrk 01:07, 4 June 2007 (UTC)

Yes, numerical analysts (like Jitse?) typically use LU decomposition (with partial pivoting, of course), then take the product of the diagonal elements.[50] However, for abstract algebra we must also consider matrices over a ring for which division is not generally available. For example, Mathematica says that it "uses modular methods and row reduction, constructing a result using the Chinese Remainder Theorem" when it cannot use the floating point methods. The computer algebra system Fermat claims to be particularly good at determinants, but I do not know the methods employed. --KSmrq^T 10:23, 4 June 2007 (UTC)

But Dodgson condensation is O(n³). I think that LU is used primarily to avoid underflow issues. Of course, per KSmrq, for non-floating point matrices LU has certain obvious problems. Silly rabbit 12:12, 5 June 2007 (UTC)

Indeed, I'd use LU decomposition. I had never heard about Dodgson condensation. I doubt underflow is an issue here. My guess would be that it is unstable, or too slow, or that nobody thought properly about it (in decreasing probability); but as I said, I'm only guessing. -- Jitse Niesen (talk) 22:55, 6 June 2007 (UTC)

Lie algebra bundle

The recently created article Lie algebra bundle starts with the word 'definition' and consists of a rather dull definition and a list of 9 references. I cannot even think of a tag to place on it (if it's not straight AfD) — any ideas? Arcfrk 18:03, 6 June 2007 (UTC)

This is a terrible start to an article on a worthy subject. Lie algebra bundles are rather important in the theory of connections (as adjoint bundles). I suggest that the best thing to do is to get the talk page going. Geometry guy 19:43, 6 June 2007 (UTC)

For now I've added a {{Wikify}} tag.  --Lambiam^Talk 19:46, 6 June 2007 (UTC)

Good call! So good in fact, that Salix Alba and I tried simultaneously to do just that. He won :) Geometry guy 20:19, 6 June 2007 (UTC)

Thank you both for so promptly obeying my command :)  --Lambiam^Talk 22:37, 6 June 2007 (UTC)

Problem of points

A relatively recent addition, but in a desperate state. It is pretty hard even to work out what it is about. Has anyone heard of this problem? If so, can you elucidate? Geometry guy 16:26, 29 May 2007 (UTC)

I've heard of it at some time or another. It's a fairly significant historical problem in probability theory. It has something to do with the fair division of a number of stakes in a game of chance given the number of points scored among multiple players (or something along these lines). It is, if I recall correctly, the European origin of Pascal's triangle. Silly rabbit 16:37, 29 May 2007 (UTC)

Thanks. This appears to be consistent with the contents of the article! Geometry guy 20:32, 29 May 2007 (UTC)

The problem is notable and famous, but I have never heard it referred to by that name. Blaise Pascal briefly mentions it, without giving it any name. de Méré's problem seems to be a different problem. –Henning Makholm 20:58, 29 May 2007 (UTC)

(I must admit, however, that Google finds a number of non-Wikipedia uses of the "problem of points" name –Henning Makholm 21:03, 29 May 2007 (UTC))

If I understand the article and the history correctly, de Méré's problem is unrelated, but Pascal (and Fermat) worked on a different problem, also posted by the Chevalier de Méré, which is a special case of the problem of points. de Méré asked Pascal to consider a game in which the players threw dice, scoring one point for each successful roll, until one player had accumulated six points and so won the game and the pot. Suppose the players must abandon the game when the score is five to four. How should they split the pot? de Méré said they should split it 3-1, but his associate said that they should split it some other way, maybe 5-4, or 2-1, or something. Pascal and Fermat agreed that 3-1 was correct.

In any case, I do believe that the problem is historically significant. -- Dominus 21:41, 29 May 2007 (UTC)

Thanks all: any chance someone could transfer these clarifications to the article? It doesn seem to be an important one, and I'm kind of busy right now. Geometry guy 21:50, 29 May 2007 (UTC)

I have rewritten Problem of points and think it to be in decent shape now. However the somewhat related article Chevalier de Méré is in need of somebody's loving attention. The current article, translated from French, tells an improbable story that de Méré managed to bankrupt himself by betting even odds on being able to throw at least one six in four throws of one fair die, and complained to Pascal that he had expected a 4*1/6 chance of winning. However, one easily computes that de Méré would actually have a few percent's advantage on such a bet, not likely to bankrupt him unless he bet his entire fortune on a single game. My sources agree that what de Méré actually asked of Pascal was an explanation of why the known better-than-even chances for throwing one six in four does not scale to better-than-even chances of throwing one double-six in twenty-four throws of two dice each. However even here the disadvantage is less than a percent, not likely to drive a non-idiotic gambler into immediate bankruptcy.

I might take a stab at this myself, but my available sources are very sparse with actual biographical information about de Méré. Anybody got something better? –Henning Makholm 22:08, 3 June 2007 (UTC)

.. on further investigation, the nonsense story about wrong odds and bankruptcy was not part of the original article that was translated from French, but was inserted later by a vandalism-only account. I have deleted it now. Some work to put reliable content in its stead still remains. –Henning Makholm 00:43, 4 June 2007 (UTC)

According to this article in French, which appeared in the Gazette des Mathématiciens, a periodical published by the Société Mathématique de France, the problem posed to Pascal was this: "how often must one throw two dice to have a priori at least a one on two chance of obtaining a double six? is it 24 or 25?" This sounds quite plausible to me; the chevalier de Méré must have known that 23 was too little and 25 sufficient.^{but see below!} I don't know if the periodical counts as reviewed, but their website states that submitted articles will be examined by the editorial board before being accepted.

Here are some bits and pieces I found:

• French writer (1607-1684). After studies with the Jesuits of Poitiers, he conquered Paris where he made himself well known in sophisticated society, and established ties of friendship with Guez de Balzac and the Duchess of Lesdiguières.[51]
• He was born in Boueux near Angoulême and was, supposedly, the first instructor of Françoise d'Aubigné.[52]
• He is responsible for quite a few aphorisms, such as: Admiration is the daughter of ignorance.

 --Lambiam^Talk 00:58, 4 June 2007 (UTC)

P.S. While plausible, the formulation of the SMF article is not actually supported by the text of the letter that Pascal sent to Fermat.[53] He writes that the man − although of great wit, not a mathematician, a grave defect − complained that "... If one undertakes to make a six with one die, one is in the advantage to undertake it in 4 ... If one undertakes to make [double six] with two dice, one is in the disadvantage to undertake it in 24. And yet, 24 is to 36 ... as 4 is to 6 ...". 01:19, 4 June 2007 (UTC)

This turned into a really nice article. Thanks and congratulations to everyone who worked on it, particularly Henning Makholm. -- Dominus 15:01, 7 June 2007 (UTC)

I'm so happy that this incidental query had such a positive outcome. I agree that Henning Makholm in particular deserves much appreciation for his efforts. Thank you! Geometry guy 18:19, 7 June 2007 (UTC)

David Eppstein for admin

I nominated one of us, David Eppstein, for administrator. If you are familiar with David's work, you are welcome to voice your opinion at Wikipedia:Requests for adminship/David Eppstein. Oleg Alexandrov (talk) 16:39, 31 May 2007 (UTC)

I'm pleased to say David Eppstein's nomination passed with 87 users in favor and none opposed, which is a remarkable show of support. — Carl (CBM · talk) 17:29, 7 June 2007 (UTC)

AfD for 1000000000000 (number)

There's some discussion about deleting it at Wikipedia:Articles for deletion/1000000000000 (number) 2nd nomin. Someone asked "Is there a Wikiproject or something discussing these? [large numbers]". I thought perhaps the members of this wikiproject might be interested. --Itub 12:55, 7 June 2007 (UTC)

Wikiproject numbers is the project that you want.--Cronholm¹⁴⁴ 14:40, 7 June 2007 (UTC)

Oops, I supposed that such a project would exist, but I tried Wikipedia:Wikiproject numbers with no success. It's with a capital N. :) --Itub 15:43, 7 June 2007 (UTC)

Importance ratings progress

I thought I would start a new section on this, so that the old ones can be archived. Today I have done some of the things I promised to do.

• I have made some progress on Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Importance. I have not yet summarized/developed the discussions here on context, but I have come up with a table of priority/importance descriptors, which I hope will prove to be more helpful than the general descriptors of WP 1.0.
• I have removed our own "peripheral/trivial" description for low importance articles and replaced it (temporarily) with the WP 1.0 "specialist" description. Untimately, I think we should replace all of the WP 1.0 descriptors by our own ones, because the former have many flaws. I intend to feed these thoughts back to the WP 1.0 project.
• I have added an additional row to the priority ratings to emphasise that there is a lower rating than low, namely "unrated". This is where the terms "peripheral" and/or "trivial" may apply, although not always. Sometimes an article could be not sufficiently relevant, or might be too specialized or technical, for it to be worth rating within this project.
• I have threaded the word "priority" a little bit more into the whole system in order to clarify the point, which User:Arcfrk articulated previously, that "importance" ratings are about how important it is for this project to have a good article on a subject, rather than an endorsement of the absolute importance of the subject. In particular, just as quality gradings use terms such as "A-Class", it may be more helpful to use terms like "Top-priority" for importance ratings. Geometry guy 22:50, 2 June 2007 (UTC)

Erm, I guess I should have said explicitly: please start making comments on Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Importance, either here, or on the talk page. Geometry guy 23:42, 2 June 2007 (UTC)

Yes I agree priority is a nicer word. The description on importance linked above seems a good start. Nice to emphesis that its for editors, if it was for readers you could say thats its OR. --Salix alba (talk) 12:21, 3 June 2007 (UTC)

I've now bitten the bullet, and drafted the "context" section. I added some information on the scope of the assessment project as well. Also, we didn't discuss articles about mathematicians: I raised the issue before, but no one commented on it. Anyway, I have proposed that we don't make substantial use of the WikiProject Biography scheme, since I believe it is flawed, particularly in the mathematics context. Full details at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Importance. The latter page is now rather long and verbose, but I thought it would be better to do it that way while the guidelines are still being developed. Geometry guy 18:03, 3 June 2007 (UTC)

Okay it looks like the plan to use X-Priority instead of X-Importance will go ahead, but the term "importance" will still be used frequently (as in "Articles by importance", "importance level" and so on). I will now also use the new importance table to update our summary table. This will be hard to get right, so other editors' input may be crucial! Geometry guy 20:37, 6 June 2007 (UTC)

Summary table now updated at: Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Assessment. Geometry guy 11:45, 7 June 2007 (UTC)

I suggest that we go ahead with renaming everything, as there have been no objections here. — Carl (CBM · talk) 14:50, 8 June 2007 (UTC)

Categories and #redirect pages

I've been looking at the new math pages for a couple of months now, and one thing I've observed really has me puzzled. From time to time, somebody hangs a "category" tag on a redirect page.

That really doesn't make any sense to me. What purpose does such a tag serve? I would just take the tags off, but I've encountered a few editors who seem quite vehement about keeping them in place (although they haven't explained why this matters in terms that I can understand). So I'm asking the question here. Should we have a general policy about category tags on redirect pages? Thanks! DavidCBryant 16:39, 7 June 2007 (UTC)

The argument in favor of it is that it allows a user to browse categories like a topical index. The argument against is that the point of categories is to categorize articles, not topics. I usually remove categories from redirects when I see them and then forget about it if someone reverts me. There general WP policy does not forbid them. — Carl (CBM · talk) 17:49, 7 June 2007 (UTC)

wikiproject logo?

I think that in general categories in redirects should be avoided, but they might be useful in a few cases when an article is called by two different names that are not universally known, and you want both names to be listed in the category to make it more accessible. I'm thinking of cases such as Zucchini/Courgette or Eggplant/Aubergine. (Note that none of those use categories in the redirect page, but perhaps they should.) I've noticed that when a redirect is listed in a category page it appears in italics, which can help in identifying them. --Itub 08:10, 8 June 2007 (UTC)

GA and math ratings

The discussions on Wikipedia talk:Good articles aimed at reforming the GA system seem to be going nowhere. Would there be support here for removing GA as one of the visible article quality classes on the maths rating template? The GA rating doesn't seem to have much to do with how we view the quality of math articles, and doesn't really fit into a linear scale with the other stub-start-b-a classes. Removing it from the scale would free us to assign GA articles "start" class if we feel they deserve it (for instance, Geometry Guy's "start" rating of Klee's measure problem, which I fully agree with), and it would avoid confusion about how GA and our own A-class rating system are supposed to interact. In any case if this change is made the GA status would still be visible in the separate GA banner on the talk page. —David Eppstein 20:21, 2 June 2007 (UTC)

I made a proposal about this above, but it is probably worth repeating it here. Basically, I proposed a less substantial change, because I think there may well be maths editors who like to have GA in the scheme, and I don't think it is necessary to remove it, only to clarify its meaning.

What I propose is a merger of B+ with GA. This would amount to the following: replace the horrible lime green colour of B+ by the darker green of GA; ask VeblenBot nicely to count and list B+ and GA articles together; and adjust some of the wording in our grading scheme to reflect the merger. In particular, an article can only be rated GA in our scheme if it is both B+ quality by our standards, and also a good article. (In particular, my rating of Klee's measure problem as Start class is entirely compatible with such a system.) Further, we can emphasise that achieving GA status has nothing to do with progression from B+ to A.

As I mentioned above, we might also want to make our B+ grading more robust, so that GA becomes, effectively, "B+ with added footnotes". Geometry guy 20:42, 2 June 2007 (UTC)

Given what I have seen of GA and its talk page, I agree with David Eppstein that needed reform seems unlikely anytime soon. That doesn't mean we must go stripping GA tags from articles, but it does mean we should eliminate GA from our ratings. As I have suggested repeatedly, to deafening silence, in principle tags like GA could be akin to barnstars, in that any group could tag articles by any criterion they prefer. (We could have "good use of subtle humor", for example.) Such tags should be orthogonal to our system, not part of it. --KSmrq^T 00:28, 3 June 2007 (UTC)

Geometry guy's merger proposal seems to rest on the assumption that some maths editors may prefer to retain the GA rating in our scheme. Being rather fond of the Polder Model, I'd prefer the merger proposal if such editors indeed exist. If not, then it's better to eliminate the GA rating (and also the section on Wikipedia:WikiProject Mathematics). So, could the people in favour of having GA in our scheme come forward? -- Jitse Niesen (talk) 04:02, 3 June 2007 (UTC)

In the current climate, I think it is rather unlikely that regulars here (G-guy included) will have a good word to say about the GA process! So I was thinking more about "the editor in the street".

However, my proposal doesn't rest on this assumption. There are other reasons why eliminating GA entirely from the scale might not be the best way forward.

• Most of Wikipedia 1.0 uses GA, and retaining it will help ensure compatibility, and enable us to argue that our B+ is equivalent to WP 1.0 GA, and not to WP 1.0 B.
• It is usually wiser to proceed slowly: we introduced B+; now let us make it a valid replacement for GA; then, later, we can consider whether we want to remove GA altogether from the scheme.
• (Closely related.) For all our misgivings about GA, and recent events, we need to be able to hold our heads high in future discussions. A too-strong knee-jerk response could marginalise us, whereas a more measured response might convince some other WikiProjects of the merits of our approach.

On the other hand, forgetting the wiki-politics, there is essentially no difference between my proposal and removing GA from our scheme. The only difference is that B+ quality articles which are also good articles will be permitted to use the letters GA instead of B+ in their quality grading. I emphasise that good articles which do not meet our B+ standards would not be so entitled, and that good article status would be even more irrelevant for progress to A Class than it is now. Geometry guy 18:59, 3 June 2007 (UTC)

I'd be very reluctant to merge B+ and GA. One reason is the political, we are in danger of isolating ourselves from the greater mass of wikipedia who do acknowledge GA. A situation where the maths pages become a law unto themselves could be very disruptive in the long term.

When I first though up B+, it was intended to be a little short of GA, generally well written articles which failed in one respect, often a lack of history or illustrations. The idea was that it could be used as a holding ground for articles that could be put forward to GA.

I've now put Klee's measure problem of WP:GA/R as I think it fails 3a of WP:WIAGA, lacking in illustrations, context of related problems, also the claimed use in computer graphics could do with a citation. --Salix alba (talk) 21:27, 3 June 2007 (UTC)

I entirely agree about the political aspect, as I mentioned already. Anyway, my compromise is rather flexible: it can instead be viewed simply as an enhancement of the current B+ rating. We already allow A-Class without good article status, so I don't a problem in regarding GA as "B+ with external quality assurance". Geometry guy 02:00, 5 June 2007 (UTC)

That is exactly how I view GA, and why I don't think B+ should be eliminated or merged. Similarly, I view FA as essentially "A class plus external quality assurance", and would not want to merge them. — Carl (CBM · talk) 02:07, 5 June 2007 (UTC)

Yes, B+ is a great innovation of this project. I'm surprised by your view of FA-Class, though: in my view there is quite a jump in quality between A-Class and FA-Class. The latter is, after all, the Wikipedia gold standard. If this project takes the view that FA is "A plus external quality assurance", then quite a few A-Class articles need downrating, and the criteria for A-Class should be strengthened! I would be very much against doing that, as I think A-Class provides an important stepping stone between GA/B+ and FA. Geometry guy 16:46, 5 June 2007 (UTC)

Perhaps "external quality assurance" isn't the right phrase. But look at the FA requirements. Only one of them relates to the content of the article independent of presentation (1b), and that one only requires that the article "does not neglect major facts and details." That's not a high fence to jump. The remainder of the FA requirements, and the bulk of the FA review process based on what I've seen, is devoted to copyediting, making sure every detail of the manual of style is followed, copyediting, etc. I just scanned through WP:FAC and it looks like most of the comments still fall into the general scope of "copyediting". One of the goals I had in mind when we made the A-class review for this project was to try to avoid that. — Carl (CBM · talk) 18:30, 5 June 2007 (UTC)

My view of Featured Articles is more pragmatic; these articles will be featured on the Wikipedia welcome page, to impress the world with the wonders of open editing. This is not a "gold standard", but something more. A specialized mathematics article could be excellent for our purposes, yet never suitable for featured status. It is not a matter of quality control, but of purpose. For quality control, Wikipedia has a peer review option (though there may be some question about who is a suitable peer).

My view of Good Articles is that the project began as an attempt to recognize small articles and others that might not merit featured status, but has since lost its way.

Where does that leave mathematics? We have very broad coverage of mathematics topics, yet almost every one of our articles could benefit from attention. Despite the excesses of the inline citation squad and the silliness of WP:V, we can surely agree that we would like each article to cite at least one place to read more. Often the English language is roughed up, as is TeX and wiki markup. Specialized articles need not overly pander to the lay reader, but even mathematicians might appreciate more genial introductions. And here and there a figure could be wonderfully illuminating for us visual thinkers. I don't trust (many of) the current GA reviewers to assist us, but their stated criteria seem close to my own. I would hope our A-class articles meet similar standards. --KSmrq^T 18:48, 5 June 2007 (UTC)

Our A-Class review is another great innovation. I agree that on the surface FAC suffers from many of the same concerns as GAC. but in practice it seems to me to be a whole different ball game, especially for technical articles. Yes, FAC editors usually criticise form, and often only add fact tags to articles, but this is frequently accompanied by a real drive to improve the article. I have participated in a couple of FACs: Encyclopedia Britannica and Equipartition theorem, but I was impressed in both cases by the result. (1b), (1c) and (4) all refer to content (as does (1a) to some extent), but (1b) is the big one, because "comprehensive" is a big word; FAC is a high fence to jump in practice. At the B+/GA level, the story is different, because the content is not fully developed, and the GA process is mostly only able to address presentational and policy issues for technical articles.

We should also be careful not to confuse FA and FA-Class. Our descriptors of FA-Class make quite clear the distinction between A-Class and FA-Class. The latter articles are described as "definitive" and "outstanding". I would not like to place such strong requirements on A-Class articles. Geometry guy 19:49, 5 June 2007 (UTC)

As to the content vrs presentation aspect of FA, this is perhaps all which could be expected. The people at FA are not in general going to be content specalists so it assesment in that factor will be hard. Maybe this is where A-class review fits in as a place where the subject specalists can assess the content. Also we should not underestimate the importance of presentation, a well presented article is more likely to get read than one which is not. Indeed this a a case where the FA process can help improve the article, there a lot of english majors there who can spot, and hopefully correct, an awkward turn of phrase. This is something which mathematicians have not. as a rule had much training in, its also something which is vital for mathematics articles aimed at a large audience. --Salix alba (talk) 20:05, 5 June 2007 (UTC)

I agree entirely. And sometimes quite amazing things happen at FAC! Geometry guy 20:13, 5 June 2007 (UTC)

Consensus?

From the above there does not appear to be consensus for removing GA-Class from our ratings, especially while this is still used and accepted by most of the rest of Wikipedia 1.0. On the other hand, we are exceptional in having a B+ class rating, and there seems to be some consensus that GA-Class amounts to B+ Class with external quality assurance (at least in issues of presentation and policy).

I therefore believe that we should update our grading scheme to reflect this consensus. I also think that the other practical suggestions I made are worthy of consideration:

1. replace the lime green colour for B+ articles with the same green colour used for GA articles; this might actually help us to incorporate our approach into the general WP 1.0 scheme;
2. list B+ and GA articles together on maths ratings pages (this is much less essential, but is mainly cosmetic).

Please comment on these concrete suggestions. Geometry guy 20:45, 5 June 2007 (UTC)

I'm going to start tweaking our grading scheme descriptors both to cover this issue, and also the issue that our articles often start off being technically correct but inaccessible, rather than accessible but needing expert input. I won't move on the two numbered issues yet (although I am sorely tempted to get rid of the lime green ;) Geometry guy 20:45, 6 June 2007 (UTC)

I don't understand this. I thought we agreed that a GA tag was orthogonal to our ratings. Indeed I thought instances were noted in which an article with serious mathematical problems nevertheless received a GA tag. For that matter, a FA tag can also be earned without a sound technical review. Once again, I claim that a checklist is the way to go. Our best articles must be technically correct and readable and include at least one citation. A featured article must be pretty (and of general interest?) as well.

---

Is it:

1. correct?
2. reasonably complete and balanced?
3. clear?
4. compelling?
5. reasonably accessible, given the topic?
6. grammatical, correctly spelled, and well typeset?
7. appropriately illustrated?
8. well linked?
9. helpful in providing references and additional resources?

---

But I repeat myself. --KSmrq^T 21:29, 6 June 2007 (UTC)

Indeed you do :) Please read the comments of Salix Alba and Carl (CBM) above. Geometry guy 22:02, 6 June 2007 (UTC)

I'm convinced by Geometry guy and Salix Alba's arguments. Let's merge B+ and GA. And please get rid of the lime green. -- Jitse Niesen (talk) 23:03, 6 June 2007 (UTC)

Changing the color is trivial. What does the merge mean, really? Would it still be possible to assign B+ ratings independent of GA? — Carl (CBM · talk) 01:51, 7 June 2007 (UTC)

Most definitely yes! Perhaps I shouldn't have used the word "merger" for my compromise proposal. Actually it is more like a definition:

GA-Class := B⁺-Class $\cap$ {good articles}.

In this way the Stub-Start-B-Bplus-A scheme is independent of WP:GA, and also GA-Class is only assigned to good articles of B+ quality. In a sense this makes WP:GA orthogonal to maths ratings, yet also keeps GA-Class within our scheme as "B+ with external quality assurance". I hope this gives some satisfaction both to supporters of GA and to editors who want to have nothing to do with it. Geometry guy 10:02, 7 June 2007 (UTC)

Further to KSmrq's suggestions above, perhaps this checklist could be part of our A-Class review process? I also think we should make sure that FA-Class math articles have been reviewed by this project, particularly for their content. Geometry guy 10:25, 7 June 2007 (UTC)

I think we would have to come up with a new name for the merge, using the GA tag will cause confusion. Changing lime green is a little tricky, {{GA-Class}} is where the colour is set and would require discussion at Template talk:Grading scheme, creating a new template could be the way forward. The colour of {{Bplus-Class}} is yellow, very easily changed.

Options seem to be

1. Create a new class the union of GA and B+
2. Treat GA as orthogonal, allow a GA tag to appear in the rating template and but with an appropriate A/B+/B/Start/Stub grading as well.
3. Just forget about GA altogether, GA listed as seperate banner on talk pages but not included in the {{maths rating}} template.
4. Keep things as they are

My preference would be for orthogonality.

I do wonder how great the problem is, are there other GA articles which have a differet maths rating, if so it might be best to put these articles on good article review. When Klee's measure problem went to GA/R there was unanamous support for delisting, this may be the case for other problematic articles.--Salix alba (talk) 10:46, 7 June 2007 (UTC)

I definitely shouldn't have called it a "merge"!! Just when there appears to be some consensus, four new proposals come along! Anyway, by "lime green" I was referring to the yellow-green colour of B+ (B-Class is yellow). Sorry for any confusion, but I did spell this out. We cannot and should not change the colour of GA-Class. Salix Alba himself has argued strongly that we should maintain compatibility with the rest of WP 1.0, so GA-Class should be kept as a possible rating. I do not see the confusion here: we already use A-Class for good articles which are better than B+. I see no harm in extending this principle and only using GA-Class for good articles of B+ quality. As Salix Alba points out, this is unlikely to be an issue in practice, as good articles which have lower quality will almost certainly be delisted.

In terms of the list, this is a compromise between "orthogonality" and "keeping things as they are". Geometry guy 11:13, 7 June 2007 (UTC)

Without orthogonality, we create the impression that an article must pass GA before it can achieve A-class. We have no consensus for such a requirement, and I think it an unsupportable idea given our current lack of comity with the GA reviewers. --KSmrq^T 16:54, 7 June 2007 (UTC)

(unindent) As far as I am aware, it has never been a requirement to pass good article to achieve A-class, neither here nor within WP 1.0 in general. I believe that there is consensus for this policy (not merely "no consensus" for its contrary). I am not aware of there being a false impression about this: plenty of A-Class articles have not passed WP:GA. Anyway, I report with pleasure (and from the above it sounds like Jitse will be happy to) that I have now replaced the horrible B+ colour with the same green used for GA-Class. This should further clarify our policy, as will some changes to the B+ and GA descriptors which I promised to make above. Geometry guy 17:47, 7 June 2007 (UTC)

I've now updated our quality grading scheme to clarify the issues discussed in this forum. Tomorrow, I will use this, together with any comments, to refine Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Assessment. Geometry guy 20:30, 7 June 2007 (UTC)

I've now refined and updated the Assessment page. Geometry guy 20:35, 8 June 2007 (UTC)

E (mathemathical constant) nominated for Good Article status

E (mathematical constant) was just nominated for Good Article status by Disavian (talk · contribs). If anyone wants to polish it to try to get it to pass, go for it. JRSpriggs 07:32, 8 June 2007 (UTC)

The review process seems to consist mostly of removing information which is allegedly "not important", such as some of the continued fractions and series. Personally, I would have preferred to leave them in the article. JRSpriggs 10:05, 9 June 2007 (UTC)

A subarticle (e.g. "Representations of e") containing some of this information may be a way forward. Geometry guy 10:24, 9 June 2007 (UTC)

We let non-mathematicians explain to us what is important, to achieve their notion of "Good Article"? No, put the information back. I read a recent claim that reviewers were not editors, so who is doing the removing anyway? Even in academia reviewers must engage in a dialog with authors; both must be satisfied, because the author's name is on the paper and the reviewers are responsible to the journal. Grow a backbone; push back. Both sides, and especially the readers, will benefit.

Often in such a process we must "read between the lines". Reject the ill-conceived fix, but try to understand what caused the reviewer to propose it. For example, maybe better organization would help; maybe the reviewer feels lost in an unmotivated disorganized sprawl. If the continued fraction is mathematically important (note: it is), then don't make the reason a mystery for the reader. Remember, most reviewers (and readers) know almost nothing about e and less than that about continued fractions.

Side note: following Bill Gosper, I like to write the continued fraction as

$e=[1;0,1,\,1,2,1,\,1,4,1,\,1,6,1,\,\ldots ,\,1,2k,1,\,\ldots ].\,\!$

Try it; the first triple is equivalent to 2, and this form makes the pattern more dramatic. --KSmrq^T 15:42, 9 June 2007 (UTC)

And it generalizes nicely to

$\exp\{x^{-1}\}=[1;x-1,1,\,\,1,3x-1,1,\,\,1,5x-1,1,\,\,1,7x-1,1,\,\,\ldots ,\,\,1,(2k+1)x-1,1,\,\,\ldots ]\,,$

which works for all values of x, except of course 0.  --Lambiam^Talk 19:45, 9 June 2007 (UTC)

On the Equilibrium of Heterogeneous Substances

Started monumental paper, please feel free to chip in. Thanks: --Sadi Carnot 15:30, 10 June 2007 (UTC)

Fermat's last theorem

I've nominated Fermat's last theorem for A-Class review. This article gets a lot of attention, pop-culture links, and (of course) vandalism, so I thought it might be worth giving the mathematical content a brush-up. Geometry guy 20:17, 11 June 2007 (UTC)

Just to clarify: this article was promoted to A-Class last October, before A-Class review was introduced in March. I (and a few others, it seems: see the article talk page) do not believe it currently meets the criteria, so some input would be most welcome. Geometry guy 23:08, 11 June 2007 (UTC)

Current activity

Does anyone have an explanation for strange behaviour of the Current activity page? I've noticed in the past that certain articles keep reappearing in the tables of supposedly newly created articles (e.g. Transformation geometry). However, recently it seems that the majority of 'New articles' are not only old, but were not even been edited on the date under which they are listed. For example, look at the list for June 10 (as an even more specific example, see Cartan's criterion, which hasn't been edited for weeks). It does make one wonder whether, conversely, all new (or renamed) articles are faithfully represented in the table. And a related question: if the name of a new article is stricken out, what does it mean? (certainly, not that it was deleted!) Arcfrk 05:06, 11 June 2007 (UTC)

You probably need to ask Oleg and/or Jitse – the current activity page is maintained by Jitse's bot, which reads input from Oleg's bot. If there really is a problem, the fault probably lies with Oleg's "Mathbot", since Jitse's bot just reformats Oleg's list (when it comes to "new" articles). Oh – the crossed out entries have been deleted from the list of mathematics articles.

I did notice some very odd activity lately. On Friday, June 8, a great number of articles were added by Oleg's bot. Then, on Sunday, June 10, the same articles were deleted from the list. I think this had something to do with Category:Modal logic and Category:Economics curves. Most likely, Oleg decided to include those two categories in a list of categories that feeds his bot, and then changed his mind. Or maybe somebody else added new categories to the list, and then Oleg took them out. It was probably something like that.

Anyway, the bots work correctly most of the time, and help us keep a handle on the math articles. I regard the occasional malfunction as par for the course. This is a volunteer effort, after all. DavidCBryant 15:27, 11 June 2007 (UTC)

That's more or less what happened: Mathbot can add categories automatically, but sometimes it makes mistakes (it isn't as good at math as Oleg), so Oleg fixes them. Geometry guy 16:01, 11 June 2007 (UTC)

One more thing. This subject was kicked around in February. You can find some relevant discussion in the archive, at Wikipedia_talk:WikiProject_Mathematics/Archive_22#New_math_articles and also at Wikipedia_talk:WikiProject_Mathematics/Archive_22#A_question_about_categories. Happy reading!  ;^> DavidCBryant 15:58, 11 June 2007 (UTC)

Thank you for the links! I had suspected at first that strange behaviour had something to do with categories, but on a closer examination, the conjecture did not hold. Namely, some articles have only one category, for example, Cartan's criterion has Category:Lie algebras; Classifying space for O(n) has Category:Mathematics stubs, and it would appear to be highly unlikely if that category appeared and disappeared from the list of mathematics on alternate days (also, the fact that other articles such as Quasi-Lie algebra with the same category as their only category did not make it to the list of new articles contradicts the conjecture). Is there another possible explanation? Arcfrk 22:16, 11 June 2007 (UTC)

You're right, Arcfrk. It's a poser. I took a look at Cartan's criterion. Oleg's bot showed it as a new article on May 24, with no activity since then. Jitse's bot shows it as a "removed article" on June 9, then as a "new article" on June 10. It sort of looks as if Jitse's bot may have hiccuped.

I noticed something similar earlier this year, with an article entitled corresponding conditional (logic). I asked Jitse about it – you can read that discussion over here. I guess I accepted Jitse's explanation (that the bot may malfunction occasionally, but it's no big deal) and now I just overlook the occasional glitch. DavidCBryant 23:19, 11 June 2007 (UTC)

Yes the weird activity is due to me. I added in Category:Modal logic and Category:Economics curves with a bunch of other categories the other day (as remarked above by David), but did not check these two carefully enough. They have a huge amount of nonmath, especially the first, so I cut them out. Sorry for the mass changes. I don't know what to do about these two categories. Comments? Oleg Alexandrov (talk) 03:07, 12 June 2007 (UTC)

The few articles in Category:Modal logic that should be counted can be included in other math logic categories easily enough, and there are very few of them, so it seems OK to me to leave that category off the list. — Carl (CBM · talk) 04:48, 12 June 2007 (UTC)

I looked into centering matrix one or two days ago, which also disappeared and reappearing in the current activity. In that case, the cause was that Oleg rolled back a few weeks' worth of edits of Mathbot at List of mathematics articles (C). I think that the issue with transformation (geometry) and transformation geometry is that Mathbot is programmed to consider them as identical, and so it puts sometimes one and sometimes the other on List of mathematics articles (T). -- Jitse Niesen (talk) 10:21, 12 June 2007 (UTC)

I now made the bot distinguish the two articles as above. Sorry for the mass rollback at the C list (I thought nobody was watching this! :) I'll pay more attention in the future. By the way, as mentioned a while ago, having more people taking a look at the recent additions is rather helpful, as that's the right time to catch misformatted articles, welcome the new people, etc. Oleg Alexandrov (talk) 16:01, 12 June 2007 (UTC)

Revisiting naming of "Boolean algebra" article

Please take a look at talk:Boolean algebra#Revisiting naming. --Trovatore 23:26, 13 June 2007 (UTC)

Infobox graph

I've put together a tentative infobox for articles on specific graphs (and, in a few cases, graph families). I'd like some feedback on the template before I deploy it on 19 articles, particularly from someone who knows more about graph theory and can better point out which properties are most important to mention. ~ Booya ^Bazooka 22:49, 10 June 2007 (UTC)

One thing I'd suggest is changing the title so it appears inside the box. You might like to look at Template:Infobox Polyhedron which is similar. --Salix alba (talk) 07:35, 11 June 2007 (UTC)

Template:Infobox graph is now operational. ~ Booya ^Bazooka 20:13, 14 June 2007 (UTC)

proposed deletion

The proposal to delete Zaimi-Marku inequality may well make sense, but the people commenting at Wikipedia:Articles for deletion/Zaimi-Marku inequality aren't being very intelligent about it yet. Michael Hardy 23:49, 15 June 2007 (UTC)

Cleaning house at the K- articles

The following articles are very weak and I am planning on prodding or AfDing them unless there is an objection here.

• K-loop-redirect to Bol loop?-resolved
• K-opt-resolved
• K-set (geometry)-resolved
• Kahan summation algorithm-resolved
• Kalman-Bucy filter-consider merge with Kalman filter-resolved
• Kampyle-PROD? On the List of curves-resolved
• Kaplansky conjecture-weak and what others?-resolved
• Kappa statistic-weak(no prod)
• Karman-Trefftz transform-no context-resolved
• Kauffman polynomial-resolved
• Kaup–Kupershmidt equation-resolved
• Klerer-May System-removed maths cats
• Knot-removed math cats
• Kulkarni-Nomizu product-resolved
• Ky Fan inequality-resolved

Any and all feedback is appreciated. Cheers--Cronholm¹⁴⁴ 05:00, 14 June 2007 (UTC)

The K-set (geometry) problem (specifically, bounding the number of k-sets that a set of n points can have) is arguably the most important unsolved problem in discrete geometry. It definitely deserves an article (a much better one than what's there). I'll add it to my to-do list, and request that you not AfD or prod it. I have no strong opinion on the others. —David Eppstein 05:12, 14 June 2007 (UTC)

Done. —David Eppstein 22:14, 16 June 2007 (UTC)

Oh, and I went ahead and merged K-opt into a larger article that gives it better context. —David Eppstein 05:19, 14 June 2007 (UTC)

I would argue that Kauffman polynomial needs a better article, but should not be deleted. I'll put it on my to-do list unless Chan-Ho gets to it first. :) VectorPosse 08:05, 14 June 2007 (UTC)

... or Salix Alba as the case might be. Thanks for the quick patch. I'll still put this on my to-do list as it could be expanded a tiny bit more. (Perhaps not much more.) VectorPosse 08:08, 14 June 2007 (UTC)

Knot now removed from maths categories. --Salix alba (talk) 09:32, 14 June 2007 (UTC)

• K-loop should be merged into and then redirect to Bol loop.
• While the Kahan summation algorithm is presented in pseudocode, it is not immediately clear what would be a better way of presenting it.
• Kalman-Bucy filter could be merged to Kalman filter.
• Kampyle is a strange case. There is the apparently unrelated Kampyle of Eudoxus, simply called "Kampyle" in this gallery of plane curves; see Weisstein, Eric W. "Kampyle of Eudoxus". MathWorld.. The equation in our article is that of the Lemniscate of Gerono; the image does not fit the equation. No references. Indeed, away with it.
• Kaplansky conjecture: don't know; is it notable? The stub states, ominously: "There are numerous other 'Kaplansky conjectures'".
• Kappa statistic: useless, delendum est.
• Karman-Trefftz transform could be merged to Joukowsky transform.
• Kaup–Kupershmidt equation has context and references; while not strong, I don't see what is gained by deleting it.
• Klerer-May System: uninformative; is it notable?
• Kulkarni-Nomizu product: no context; is it notable?
• Ky Fan inequality: ditto.

 --Lambiam^Talk 11:52, 14 June 2007 (UTC)

I've expanded Kulkarni-Nomizu product slightly. This old-fashioned operation in differential geometry is never going to be a great article, but it is notable. I've also made minor tweaks to some of the others. It is usually easier to provide redirects or add links to backlinks than to PROD articles. Michael Hardy may be able to provide notability for Ky Fan inequality, as he has edited it in the past. Geometry guy 12:10, 14 June 2007 (UTC)

I have tweaked Ky Fan inequality and added a reference. Gandalf61 13:30, 14 June 2007 (UTC)

Kaplansky conjecture is notable, it is related to Kadison idempotent conjecture, aka Kadison-Kaplansky conjecture, and Baum-Connes conjecture. The statement about numerous other Kaplansky conjectures is correct, but misleading (there are, but why mention them here instead of writing a separate article?). Arcfrk 15:58, 14 June 2007 (UTC)

And it is the List of statements undecidable in ZFC, which is a substantial claim to notability (as Kaplansky's conjecture, which should be straightened out; I'm not sure which is idiomatic). Septentrionalis PMAnderson 16:05, 14 June 2007 (UTC)

This seems to be yet another Kaplansky conjecture. Geometry guy 16:26, 14 June 2007 (UTC)

PS. I'm a bit surprised that Baum–Connes conjecture is still red. Can someone make a stub? Geometry guy 16:41, 14 June 2007 (UTC)

Kaplansky made dozens of conjectures. I've spent an hour reading Math Reviews, and the vast majority of them are either better known by other, more descriptive names, or referred to as Kaplansky's conjecture. I suggest that the latter be made into a disambiguation page. The conjecture mentioned by PMAnderson is one of the notable exceptions. Arcfrk 16:31, 14 June 2007 (UTC)

I've added more info from this page, and prepped the article to become a dab at a later date. Geometry guy 22:07, 14 June 2007 (UTC)

PS. Credit to Cronholm for turning another redlink blue!

• Kappa statistic should probably be a dab between Fleiss' kappa and Cohen's kappa. I have no opinion on whether either of them is notable, and one of them appears to be a trivial generalization of the other; I'm only judging from the articles. Septentrionalis PMAnderson 16:13, 14 June 2007 (UTC)

I guess we need one of our expert statisticians to comment on this one. Geometry guy 22:44, 14 June 2007 (UTC)

I have found a webpage on the Lemniscate of Gerono that compared its equation to the rather similar equation of the Kampyle of Eudoxus. In the conviction that this was the source of confusion resulting in the wrong equation to be ascribed to the Kampyle, I've rewritten the latter article (still a stub) and moved it to Kampyle of Eudoxus. For simplicity, I've omitted a parameter making this a family of similar curves, where the similarity transformations (rescaling) leave the origin fixed; after all, other similarity transformations (e.g., rotation) are usually not dealt with either.  --Lambiam^Talk 22:49, 14 June 2007 (UTC)

Proposed merges to Partial fraction

I've proposed that the two articles named Partial fraction decomposition and Partial fraction decomposition over the reals be merged into the article named Partial fraction. You can explain why this is a terrible idea at, respectively:

• Talk:Partial fraction#Merge with Partial fraction decomposition, and
• Talk:Partial fraction#Merge with Partial fraction decomposition over the reals.

 --Lambiam^Talk 08:13, 18 June 2007 (UTC)

More weak stubs

Hello again everyone, thanks for your swift action on the K articles (Kappa statistic is the only one left). I have found more articles in need of attention so here goes. :)--Cronholm¹⁴⁴ 06:26, 17 June 2007 (UTC)

I guess I need to make myself a little more clear. These articles will be on AfD if they don't improve.--Cronholm¹⁴⁴ 06:26, 17 June 2007 (UTC)

Weak:

• Kaczmarz method--one sentence
• Kendall's W--three sentences
• Jacobi-Lie bracket--two sentences
• Jarnik's theorem--one sentence
• Jensen-Shannon divergence--two sentence and two references...
• Jenkins-Traub method--one and one source

Jacobi-Lie bracket is a clear AfD case. Arcfrk 06:48, 17 June 2007 (UTC)

Isn't it just a redirect to Lie derivative? Geometry guy 09:27, 17 June 2007 (UTC)

I have cleaned up everything but Kendall's W (which was already done before I got there, thanks Lambiam and David) and Jarnik's theorem. Furthermore, I think that the latter might be wrong, the Jarnik's theorem I found has to do with diophantine approximation. I need input on this one. Also I am going to dab Kappa statistic if their are no more objections. cheers--Cronholm¹⁴⁴ 04:21, 18 June 2007 (UTC)

I still think we need a statistician to look at kappa statistic. It seems to be that this has developed into a general concept of which Cohen's kappa and Fleiss' kappa are the key examples. I've added a bit to the lead, anyway. Geometry guy 12:16, 18 June 2007 (UTC)

I guess I will give it more time, hopefully Michael will fix it. I saw him playing with it.--Cronholm¹⁴⁴ 17:46, 18 June 2007 (UTC)

Well, we have worse stubs than this one. Jarnik's theorem is more troublesome. I wasn't able to find any reference to such a result known by this name. Of course Vojtech Jarnik proved many things, and there are a couple of notable results called Jarnik's theorem, one in diophantine approximation, another about the existence of lim sups of difference quotients (mentioned by Erdos in the Annals, no less). However, neither of them are the result which this article is attempting to state. Geometry guy 18:29, 19 June 2007 (UTC)

Other:

• Juxtaposition--shouldn't be a math article
• Joint Board for the Enrollment of Actuaries--I don't know what to do with this

I've removed the math cat from the second of these. The first is a wiktionary link, so I've removed it from the list, as suggested. Geometry guy 09:56, 17 June 2007 (UTC)

Boolean algebra again

The term "Boolean algebra" usually means (to mathematicians) a type of algebraic structure, and (to non-mathematicians) a way of manipulating propositional variables. My last try at gathering a consensus on how to disambiguate, went nowhere, and we still have the problem. I'm trying again at talk:Boolean algebra#naming -- trying again, hopefully with a statement of the problem that takes into account what I learned from the last discussion. --Trovatore 08:08, 20 June 2007 (UTC)

Oh, of course sometimes mathematicians, also, use the "way of manipulating variables" sense of the word. The point is that there are two quite distinct meanings, and there are in fact two articles (though both need significant improvement), but Boolean algebra itself needs (IMHO) to be a disambiguation page because neither of the two well-demarcated meanings is in fact primary. --Trovatore 09:00, 20 June 2007 (UTC)

The reason to have different articles for Quotient ring and for Modular arithmetic, for example, is not that one is a count noun for abstract algebraic structures and the other a mass noun for a collection of mathematical operations, but that modular arithmetic involves only one very specific class of quotient rings Z/mZ. Suppose that class was an object of serious mathematical study in its own right, as a subfield of Ring theory, and we had an article on those "Modular rings" (as they are sometimes called). Then (in my opinion) there would be no very good reason to separate the articles on (1) the algebraic structures that are these "modular rings", and (2) the "modular arithmetic" of such structures. I still don't see what makes Boolean algebra so different. We could of course make a dab page, both of whose disambiguating links point to the same article. :) But please weigh in with your insights at Talk:Boolean algebra#naming -- trying again.  --Lambiam^Talk 11:17, 20 June 2007 (UTC)

This reminds me a bit of a common situation in which editors debate the choice of words in the lead of an article whose content is inadequate. In that case, a good piece of advice is to improve the content and then write the lead. Any disagreements about the content can then be resolved during the course of improving the article rather than on the talk page, and once the content is good, it is usually pretty easy to write a good lead. Maybe something like that is needed here. Once the content is right, the names of the articles might be less contentious. Geometry guy 11:45, 20 June 2007 (UTC)

Having said that... a compromise solution occured to me (see the article talk page), motivated by the observation that there is a category here, Category:Boolean algebra. Now, like any self-respecting category, this ought to have a main article, presumably called Boolean algebra, which should neither be a dab, nor focus on one of the particular meanings of the term. The particular meanings could then be elaborated in subarticles. Geometry guy 16:56, 20 June 2007 (UTC)

We have two meanings, and two articles. What's wrong with a dab header from each to the other? Why do we need to have everybody click through a dab page? Septentrionalis PMAnderson 18:06, 20 June 2007 (UTC)

Mainly because of links. Editors repeatedly add wikilinks to Boolean algebra, intending one meaning or the other (and generally it's quite well-defined which meaning), without bothering to check whether the article actually reflects that meaning. I don't see that changing. If the link goes to the wrong article it may stay that way for a long time. If it goes to a dab page, presumably someone will notice and do something about it. --Trovatore 18:12, 20 June 2007 (UTC)

The main article I am suggesting would, of course, begin with a dab header to the two main meanings. The advantage of this approach, however, is that even if editors don't notice that they should disambiguate, a link to the main article is still useful, and possibly even educational. Geometry guy 18:44, 20 June 2007 (UTC)

But it's not the article that either sort of editor is intending to link to. --Trovatore 19:27, 20 June 2007 (UTC)

So an editor of either persuasion will at some point fix it. Meanwhile, readers might even benefit :) Geometry guy 19:39, 20 June 2007 (UTC)

I don't see how, as in my opinion there is no sensible way to write such an article, except by making it primarily about the mass-noun sense, which gives us the current linking problem, but just reversed. --Trovatore 19:44, 20 June 2007 (UTC)

No, there is also George Boole, the algebra of sets, and numerous other issues in the category to be discussed. But, if your mind is so made up, Trovatore, that you are not able even to imagine alternatives to your point of view, then why bring the issue to WT:WPM? I made another suggestion above, which is to make the content of the articles match your vision. You may be contested, because this is not www.trovatore.com, but at least content would be added to the articles. Geometry guy 20:10, 20 June 2007 (UTC)

Signal subspace

Could someone take a look at the above page? It's newly created, and a little incoherent at the moment. I've wikified a couple of the links, but anyone who's familiar with the term might want to have a look. Thanks! -- simxp (talk) 10:21, 20 June 2007 (UTC)

What's the problem? It seems clear to me, except for the use of "almost completely" for "not quite 100%" instead of the usual mathematical meanings of "almost". I'll see if I can fix that. Septentrionalis PMAnderson 17:58, 20 June 2007 (UTC)

You were looking at a version several revisions later than the initial request. The diff between the versions can be seen here.  --Lambiam^Talk 23:33, 20 June 2007 (UTC)

Mathematical eyes sought

Over at integral, the fabulous Mathematics Collaboration of the Month, Loisel and I are discussing an image purporting to show the difference between Riemannian and Lebesgue integration. There is some prior unresolved discomfort with the image at Lebesgue integration, and the section of that article in which the image appears ends with the completely unacceptable remark: "See the discussion page." (May I just say, yuck.) The French, German, Russian, and Japanese pages do not use the image.

I'm keen on fostering intuition, and work hard to provide appropriate images. The question for all you analysts and pedagogues: Is this image correct and helpful? Please come share your views! Thanks.

(Feel free to guide evolution of the integral article in other ways as well; one prior view is here.) --KSmrq^T 18:00, 17 June 2007 (UTC)

I think both points of view have some validity here. The image is partly helpful in understanding the difference between Riemann and Lebesgue, but also partly misleading. Roughly speaking, Riemann integration involves slicing up the domain, Lebesgue integration the codomain, and the picture captures this. Although it does not represent how the Lebesgue integral is usually defined (see Talk:Lebesgue integration#The 'intuitive' interpretation, the "unresolved discomfort" linked above), it could be defined in this way.

The key difference between the two forms of integration is that Riemann integration exploits the connected topological structure of the domain, whereas Lebesgue integration does not. On the one hand, this means that Lebesgue integration generalizes to any measure space. On the other hand, the Riemann approach can be extended to integrate the derivative of any function (the generalized Riemann integral of Kurzweil and Henstock), whereas the derivative of $x^{2}\sin(1/x^{2})$ is not Lebesgue integrable across zero (the absolute integral diverges); indeed no theory of integration on measure spaces can handle such a function because its integrability relies on local cancellation, one of the deepest aspects of real and harmonic analysis.

I would therefore suggest that the image could be helpful, but its use must be qualified explicitly. I will make a start at Lebesgue integration by removing the reference to the talk page, which is not only unacceptable (to delicate souls like KSmrq and myself), but not permissible on Wikipedia. Geometry guy 20:12, 17 June 2007 (UTC)

PS. I second KSmrq's encouragement to work on Integral, although I have not been nearly so virtuous as he has in this respect!

The picture does not help foster my intuition of the Lebesgue integral at all. I prefer the "splitting up the range" versus "splitting up the domain" approach that Geometry guy said above (besides, that's basically what's going on). The picture actually makes me think that I don't understand the Lebesgue integral (while, as it stands, I believe that I do)l. The picture does not look that good (in my eyes) anyway. I suggest that it be done away with.

And I should add, I don't like the picture because when computing "area between curves" in a Calculus 2 course, sometimes integrating along the y-axis is more helpful; it seems to me that the picture confuses the Lebesgue integral with this kind of approach. –King Bee ^{(τ • γ)} 20:23, 17 June 2007 (UTC)

Well I made a poor first effort at Lebesgue integration, but that might be the best way to encourage others to improve it :) Geometry guy 20:27, 17 June 2007 (UTC)

In the real analysis class that I teach, I explain that the Lebesgue integral involves splitting up the y axis instead of the x axis, and I make basically the same drawing as the figure. Loisel 20:30, 17 June 2007 (UTC)

Is this not like arguing about whether (a+b+c)+(a+b)+(a) is the same or different from (a+a+a)+(b+b)+(c)? JRSpriggs 08:40, 18 June 2007 (UTC)

I don't like the Lesbegue integration diagram because it gives the impression that Lesbegue integration just consists of replacing $\int y(x)dx$ with $\int x(y)dy$. It does not give a intuitive feel for why the Dirichlet function, for example, is Lesbegue-integrable even though it is not Riemann-integrable. The "contour map" explanation that goes alongside the diagram in the Lebesgue integration article suffers from the same problem. How do you draw contours on the Dirichlet function ? Seems to me that if you can draw contours then the function is Riemann-integrable anyway, so this explanation begs the question. Gandalf61 09:40, 18 June 2007 (UTC)

Yeah, that's what I was getting at with my "area between curves" thing above. I agree entirely; most of the interesting functions that are Lebesgue integrable cannot be "graphed" or "drawn." –King Bee ^{(τ • γ)} 10:19, 18 June 2007 (UTC)

I think this is a red herring. These pictures have nothing to do with which functions are integrable: they are about how the integral is defined. Indeed the difference being illustrated (partition of codomain vs partition of domain) is irrelevant to the question of which functions can be integrated. The Dirichlet function can be integrated by Riemann summation: all you have to do is allow the width of the strips to vary with position in the limiting process.

The Dirichlet function has Riemann sums, but by an appropriate choice of partitions we can make the Riemann sums over a unit interval converge to either 0 or 1. Since the limit of the Riemann sums depends on the choice of partitions, the Dirichlet function is definitely not Riemann-integrable - the fact that we can engineer the paritions to make the Riemann sums converge to the "right" answer is irrelevant. Indeed, the Dirichlet function is used as an example of a function that is not Riemann-integrable in the Riemann integral article. Gandalf61 21:44, 18 June 2007 (UTC)

Yes, but it is generalized Riemann integrable, Gandalf: all Lebesgue integrable functions are. For all ε, there exists a gauge δ(x) such that any δ-fine Riemann sum is within ε of the integral. The (essentially trivial) modification of the Riemannian definition is to let the control parameter δ depend on position. Geometry guy 21:59, 18 June 2007 (UTC)

The "contours" in the Lebesgue approach are given by a simple function approximating the given function. They are typically undrawable, but then, the Weierstrass function can't really be drawn either.

As I mentioned in above, the key difference between the two definitions is that the Lebesgue approach generalizes to measure spaces (whereas the Riemann approach does not), while the Riemann approach allows local cancellation (the Lebesgue approach does not).

It is certainly important to discuss differences between which functions are integrable in different theories, but this is a separate issue and requires a separate discussion. Geometry guy 12:51, 18 June 2007 (UTC)

Integral of sqrt — Riemann and Lebesgue

Consider the figure shown right. I claim that it is exactly the right picture for both a Riemann sum and a Lebesgue measurable "simple function" sum. The simple function consists of piecewise constant steps, and the measure of each step is the length of the real interval under it. Thus the sum of the Lebesgue integral is exactly the same as the sum of the Riemann integral.

The example function, f(x) = √x, is deliberately monotonic. A non-monotonic function could have separated intervals with the same simple function value. The measure for that term of the sum would combine those interval lengths. But in neither case is it correct to depict the summation using horizontal slabs.

Teaching is an art, and each class and each teacher is different. If Loisel finds it helpful to use incorrect figures in an attempt to convey correct intuition, best of luck. I am not comfortable with that approach, and don't think Wikipedia should follow suit. Need I add, IMHO? --KSmrq^T 17:21, 18 June 2007 (UTC)

This is both a Riemann sum (provided one allows variable width strips) and a simple function, but so what? Just because you can draw a picture which fails to illustrate the difference between the two methods of summation doesn't mean that they are the same. In your case the simple function has the form

$\sum _{i=1}^{n}a_{i}1_{[x_{i-1},x_{i}]},$

where $0=x_{0}<x_{1}<\cdots <x_{n}=1$. Now try drawing a picture to illustrate a simple function of the form

$\sum _{i=1}^{n}b_{i}1_{[x_{i-1},1]}.$

(With $a_{i}=\sum _{j=1}^{i}b_{j}$, this is the same function.)

The intuition that Loizel is attempting to capture is that the Riemann integral can be obtained by a limiting process in which the width of the strips tends to zero, whereas the Lebesgue integral can be obtained by a limiting process in which the height of the increments tends to zero: this is a fundamental distinction between the two methods. Just because Loizel's picture doesn't convey that intuition for you and your class does not mean it is "incorrect". It just needs to be properly explained. Geometry guy 17:50, 18 June 2007 (UTC)

Sorry, your example is not cast in proper "simple function" form, which partitions the domain as pre-images of the range:

${\begin{aligned}s&{}=\sum _{i=1}^{n}a_{i}\,1_{A_{i}}\\A_{i}&{}=\{x\colon s(x)=a_{i}\}.\end{aligned}}$

Nor is there a limit, per se, merely a supremum over all suitable s. The step heights a_i are always vertical, the measurable sets A_i are always unions of horizontal intervals, the measures are sums of those interval lengths, and so each term is a collection of vertical slabs.

I agree that an s with more steps, more "vertical partitions" as it were, can more closely approach the supremum. I agree that we might like to tickle the intuition. But I contend that horizontal slabs do not match the definitions; they do not correspond to anything in the sums.

We are allowed only a finite number of heights for s, and the support of each height must be a measurable set. And although we require s ≤ f, the heights need not touch the function. (In the square root example, we could use s = ¹⁄₂ if ¹⁄₃ < x < ²⁄₃, and s = 0 otherwise.)

It might be possible to depict something showing the finite number of distinct range values, maybe using horizontal lines traversing the entire width of the plot. But, please, no sum of horizontal slabs. --KSmrq^T 19:19, 18 June 2007 (UTC)

Lebesgue integral and simple function both define a simple function to be a finite linear combination of indicator functions of measurable sets. That does not mean your definition is wrong, of course, only that there are different points of view. There are several minor variations that one can employ in the definition/construction of the Lebesgue integral. In particular, it could be defined in terms of horizontal slabs, even if this is neither a common definition nor your preferred definition. Let me emphasise, though, that I am not wholeheartedly endorsing horizontal slabs picture. I just think there is something being captured here that some editors seem to value. But it seems your mind is made up. Geometry guy 20:01, 18 June 2007 (UTC)

I'm vigorously asserting a position, which is not quite the same thing. ;-)

An ideal image would show both the similarities and the differences of Lebesgue and Riemann. Strengths of Lebesgue include two kinds of generality: peculiar functions and diverse domains. Weaknesses include the need for measure and for absolute convergence (if |f| doesn't work, Lebesgue fails). I think the key novelty is that although a measurable set can be a collection of intervals, it can also be much more flexible than that. Thus the function

${\begin{aligned}f\colon [0,1]&{}\to \mathbb {R} \\x&{}\mapsto {\begin{cases}0,&{\text{if }}x\in \mathbb {Q} \\1,&{\text{otherwise}}\end{cases}}\end{aligned}}$

is a "simple function" (in the technical sense!), and the success of the Lebesgue integral in coping with it is all down to the fact that the pre-image of 0 and the pre-image of 1 (the only two values in its image) are both measurable sets. We have no need for a limit of increasingly thin horizontal slabs!

This we cannot depict; but we can make the same point by using zero (or arbitrary values) at only a finite number of exceptional spots.

I am, of course, thinking aloud, searching for a concept and an image than comes closer to everyone's ideal. --KSmrq^T 22:00, 18 June 2007 (UTC)

You are indeed: I encourage you to learn about the generalized Riemann integral, which I have mentioned in several of my posts here, but (apart from your reference to absolute integrability) you appear not to have responded. The problem with your approach is that you are trying to do several different things at once. The generality of an integral in terms of the functions it can integrate, and it terms of the spaces on which it is defined, are really two quite different ideas. Conflating them just adds to the confusion. Geometry guy 22:06, 18 June 2007 (UTC)

Why do you think I was conflating kinds of functions and kinds of spaces? I deliberately listed them as two separate items! I have not mentioned it, but I was already familiar with Henstock–Kurzweil and have been thinking about whether to bring gauges into this. In fact, by replacing a constant delta over all sub-intervals by a gauge function assigning a delta to each tag location we can integrate a broader class of functions than Riemann or Legesgue; however, Lebesgue apparently generalizes to other spaces more nicely. (Ironically, I actually had Schechter's page open for inspiration as I was typing my previous post!) More to the point, the Henstock–Kurzweil integral clearly does not use horizontal slabs; it builds on Riemann sums.

Set that aside. Is not my final example a death blow to the horizontal slab idea? (This is, of course, the kind of nowhere continuous function that Gandalf61 wanted to address.) My question is, what kind of image retains the idea of a finite collection of range values, but without the slabs? Can we inspire intuition about measurable sets with a picture? --KSmrq^T 03:49, 19 June 2007 (UTC)

Because the purpose of this picture is not to explain the fact that more pathological functions can be integrated by the Lebesgue integral than the Riemann integral; it is to explain the idea that by partitioning by codomain instead of domain, the integral can be defined on a wider class of spaces.

I agree indeed that it is precisely to the point that the Henstock–Kurzweil integral "does not use horizontal slabs; it builds on Riemann sums": this means it is a generalized Riemann integral, not a generalized Lebesgue integral (it makes no sense on measure spaces). But we seem to be talking at cross purposes because of different nuances in the words. For instance, in your final example, there is just one undrawable slab. The slab picture is hopeless for inspiring intuition about ungraphable functions, but that is not its purpose. Geometry guy 10:59, 19 June 2007 (UTC)

I think this discussion is resolved with the following reference:

Folland summarizes thusly: "to compute the Riemann integral of f, one partitions the domain [a,b] into subintervals", while in the Lebesgue integral, "one is in effect partitioning the range of f".

Loisel 22:10, 18 June 2007 (UTC)

But the meaning of this statement must be explained, Loisel. We are not in the business here of promoting a point of view, but in providing encyclopedic information about a topic. The point of view you express has some validity, in my opinion (see above), but it must be accompanied by riders and explanation, or it is simply misleading.

Please everyone, look for compromise here. You know it makes sense! Geometry guy 23:11, 18 June 2007 (UTC)

Ordinarily, for math articles I'm not too much about "compromise" and "NPOV" and "no original research", because math is typically true or false. Unforunately in this case, it is quite obvious that there are strong opinions. In this situation, I will resort to WP:NPOV, WP:VER and WP:NOR. If you want to modify this part of the article, you are welcome to do it, subject to WP:NPOV, where you must phrase things in a neutral way, WP:VER, where you must cite a source which says pretty much exactly what you want to say, and WP:NOR, where you cannot come up with your own explanation.

As far as I know, Rudin and Lang have said nothing on this subject. You are welcome to find a source that says something else. You are also welcome to add something like "Rudin and Lang draw no such analogy between the Riemann and Lebesgue integral". Loisel 00:30, 19 June 2007 (UTC)

Jawohl, mein General! Arcfrk 00:38, 19 June 2007 (UTC)

Ah, if you want, you can actually give a formula, by gluing the right bits of Folland, which does give a formula in terms of the horizontal slices of the function, like the picture. Loisel 00:47, 19 June 2007 (UTC)

So you are saying that for a simple function that takes on two values, say a and b with a < b, Folland gives the formula for the sum (b-a)v + a(u+v), where u is measure of the preimage of a and v is the measure of preimage of b, instead of simply au + bv? I don't have access to the book right now, so I can't check myself. --C S (Talk) 01:23, 19 June 2007 (UTC)

More or less, although it's of course not said in such a simple way. You have to look up the theorem that Folland gives, which says that there is a sequence of simple functions converging to f in L^1, and how to build this sequence. Then you glue it with the definition of the integral of a simple function. Loisel 02:33, 19 June 2007 (UTC)

I just realized I'm not sure your formulae are right, but what I replied is true, I think. Loisel 02:35, 19 June 2007 (UTC)

I have two copies of Rudin (real and complex, and principles of analysis), which one were you looking at? Also, I am compiling a bevy of resources that talk about Lebesgue, I think I will stick all of the excerpts in my sandbox and link them here if there are no objections.--Cronholm¹⁴⁴ 00:53, 19 June 2007 (UTC)

R&C analysis is the one that discusses the Lebesgue integral (chapter I). I may be wrong, but your PoA one is probably the first year Riemann integral text, in which case it does not talk about the Lebesgue integral. I don't think his other books discuss the Lebesgue integral either. Loisel 01:07, 19 June 2007 (UTC)

Thanks, I will look there first. I have found four books so far and I am about halfway through my books.--Cronholm¹⁴⁴ 01:12, 19 June 2007 (UTC)

Here it is User:Cronholm144/Lebesgue. I gathered together all the resources that bothered to address the integration geometrically(many didn't). From my own reading, I can see how the picture could be misleading, if we are to include it, (I am leaning against it) we must be extremely careful about how we explain it. The possibility exists that the reader might just see the picture and and come away with a flawed understanding of the concept. It seems to me that it might be more of a liability than help.--Cronholm¹⁴⁴ 02:04, 19 June 2007 (UTC)

I feel some of Geometry Guy's comments need to be expanded on, particularly the comment on how the picture does not match the usual definition of the Lebesgue integration but does match an "unusual" definition. The picture, to me, clearly indicates a definition of the Lebesgue integral as an improper Riemann integral. I think Loisel would agree that what is "really going on" is we are taking limits of sums as the mesh of the subintervals of the range gets smaller; each sum has a term that looks like (length of subinterval with bottom endpoint y) * (measure of all domain points x that map to greater than y). The function that for every y gives the measure of all domain points x that map to greater than y is in fact a Riemann integrable function, as it is monotone decreasing.

Let me emphasize there is no need for simple functions here, because we are doing a Riemann integration. I think part of the problem in this whole discussion is that Loisel wants to do something like I just explained but also wants to use the machinery of simple functions. However, when using simple functions, the ahem, simplest thing to do is take the sum in the obvious way, i.e. each value of the simple function gets multiplied by measure of the value's preimage, not to create these "slabs" as in the picture. On the other hand, if one wants to think of the Lebesgue integral as the result of slicing up the range and doing an analogous thing to the Riemann integral, one can! It is then in fact a real (improper) Riemann integral. --C S (Talk) 02:32, 19 June 2007 (UTC)

Well, for the purpose of the article, I want nothing more than to quote Folland.

For the purpose of math...

The notion that partitioning the range is of crucial importance in many proofs of the Lebesgue integration theory, starting with the density of continuous functions in L^1 and including Chebyshev's inequality, etc...

In addition, partitioning the range is not equivalent to partitioning the domain. If you partition the range in intervals and do the right thing, you get the Lebesgue integral. If you partition the domain in intervals, you get Riemann and not Lebesgue. Loisel 02:45, 19 June 2007 (UTC)

Illustration of a Riemann integral (top) and a Lebesgue integral? JPD (talk) 10:58, 19 June 2007 (UTC)

Illustration of a Riemann integral (top) and a Lebesgue integral? JPD (talk) 10:58, 19 June 2007 (UTC)

I don't think so. To my trained eyes, they look the same except for the color. Loisel 15:06, 19 June 2007 (UTC)

It does capture something for me, because in the first picture the strips have equal width, whereas in the second, the height differences are equal. Perhaps the function could be made less flat to make the difference more pronounced?

On the other hand I agree with Loisel's earlier comments that the slab picture isn't really a Riemann integral: you need the function to be invertible for that. The indicator function of the irrationals, as KSmrq pointed out, is a counterexample to such an interpretation of the integral of a simple function. Geometry guy 18:42, 19 June 2007 (UTC)

If you are referring to Loisel's response to my earlier remarks, it's not clear to me that s/he (and you) understand my comments. The function need not be invertible. But slicing up the range does in fact give a Riemann integral of a different function. This function is obtained by taking the measure of all points in the domain that map above a certain value. So if the original function is f, then the new function F(y) = measure of the set of x such that f(x)>y. The Riemann integral being illustrated is then simply \int[0, \infty] F(y)dy (assuming f only took nonnegative values). It seems to me that this is exactly what you and Loisel have been talking about with the horizontal slabs. There is no need for simple functions here as you can just take the Riemann integral directly. --C S (Talk) 06:51, 20 June 2007 (UTC)

Thanks for explaining, Chan-Ho, and sorry I didn't get it before. This is quite clever, and I agree that this is one way of looking at what is going on, although one might argue that computing measures before integrating is "cheating" in the context of the Riemann integral. Geometry guy 11:19, 20 June 2007 (UTC)

To Chan-Ho Suh: If I understand you correctly, I think you are using the wrong Riemann integral to approximate the Lebesgue integral. You want

$-\int {y\,dF(y)}$

which is actually a Riemann-Stieltjes integral. JRSpriggs 11:47, 20 June 2007 (UTC)

Hehe, nope, I wrote what I wanted. Just take a Riemann sum of the integral I defined and a Riemann sum for the one you defined. Rearrange. Rinse and repeat. You will see they give the same answer with the appropriate choice of y in the subintervals. Your integral is corresponds to the usual picture for an integral of a simple function, but my point is that "my" integral corresponds to a horizontal slab kind of picture: for nice functions, each term in a Riemann sum for the integral will indeed be horizontal slab (or a disjoint union of such). I prefer to use just a Riemann integral since it makes the following pedagogical point better: a Lebesgue integral is nothing more than an improper Riemann integral of a related function. Of course, as Geometry Guy mentions, it may be kind of "cheating" as one still needs the Lebesgue measure theory, but I wasn't aware I was trying to get away with something here :-). --C S (Talk) 18:12, 20 June 2007 (UTC)

Oh. Are you doing integration by parts and did not tell me? Using that y=0 at the lower limit and F(y)=0 at the upper limit (when y=+infinity). I guess the joke is on me. JRSpriggs 07:00, 21 June 2007 (UTC)

The visual distinction here is almost invisible to me, and I know what point is being made. What's wrong with the traditional illustration of the Lebesgue integral, with horizontal slabs? Septentrionalis PMAnderson 02:15, 20 June 2007 (UTC)

Riemann versus Legesgue as vertical versus horizontal slabs

Late to the party, eh? What's wrong with it is the question on which this discussion began (see right). --KSmrq^T 03:02, 20 June 2007 (UTC)

Fashionably late, I would say :) The use of the word "traditional" here is interesting, though. Geometry guy 11:19, 20 June 2007 (UTC)

To add something concrete to the discussion, see (green) Rudin's proof of theorem 1.17 on simple functions: every non-negative measurable function is the pointwise limit of a non-decreasing sequence of simple functions. The technique is to divide up the range into finer and finer rectangles. The link with Lebesgue integration is clear: monotone convergence. Silly rabbit 12:55, 20 June 2007 (UTC)

Proposal for a new image

So here's an idea I'll throw out for a new image, which maybe can be hammered out into something agreeable to everyone. Draw a function that oscillates infinitely many times. Start with some up and down humps that get smaller and smaller, then put some "dot dot dots", then some more humps that get larger. When you draw horizontal slabs for a level, there will now be pieces that get smaller and smaller. So hopefully the idea that is conveyed is that for a slab level you need to multiply the height of a slab by a "width", but here the "width" must be some kind of measure thing.

This kind of picture would (hopefully) avoid the the "it's just inverting the function and Riemann integrating" pitfall that several people have mentioned. On the other hand, it illustrates a right way to interpret the Lebesgue integral as a Riemann integral that has been discussed above. In particular, it still captures this slicing up the range idea, while indicating that all the "nastiness" gets pushed to understanding measures of these preimage sets. Boy, I guess it'd be nice if I actually made a picture, but I'll leave that to someone more industrious for now. --C S (Talk) 18:50, 20 June 2007 (UTC)

Mathematics portal

Interest in maintaining the portal seems to be at an all-time-low. I guess it had been heroically and almost single-handedly maintained by Fropuff for a while, but he appears to be less active on Wikipedia these days: Tompw was another vital contributor, who may or may not still be interested in the project. The "article of the week" would have broken last week and this week, if I had not repeated Golden ratio and then copied an old portal article (the Pythagorean theorem) into the latest slot.

Although I maintained the page in Fropuff's absense (with Fractal, Map projection and Golden ratio, and thanks to suggestions and advice from this forum), I doubt I am sufficiently heroic to keep this up on my own (and admire Fropuff all the more that he did). I would therefore propose to continue the process, which I started this week with Pythagorean theorem, to recycle old portal articles in order, omitting only those which no longer meet our standards. Comments welcome, volunteers even more so.

In addition to this proposal, there is a more general point I would like to make. One of the reasons I would prefer to reuse old portal articles (for the time being) is that it is extremely difficult to find additional mathematics articles which are suitable. Among our articles of Bplus quality and above, the ones that are sufficiently accessible and appealing for the portal have already been used. Some editors may have noticed that in {{maths rating}}s, I am being a bit harsh on articles that are less accessible than they could be (and have tweaked the B and Bplus descriptors in the grading scheme to reflect this). This does not mean I believe that an article on an advanced mathematical topic should be accessible to the layman, only that each article should be as accessible as is appropriate for its content.

I encourage everyone to create more articles that could appear on the portal! Geometry guy 19:59, 19 June 2007 (UTC)

Hmmm, probably "portal interest" is an oxymoron, and "apathy" would be a more appropriate adjective. I wish I had the talent for controversy that KSmrq has used to generate interest in Integral! Anyway, things being as they are, and the portal being dull, I've recycled some old articles. This will satisfy the "article of the week" up to week 40 of this year. Can someone set a wiki-alarm clock? Geometry guy 23:00, 20 June 2007 (UTC)

If you want controversy, pick someone's favorite article and have the Portal:Mathematics cite it as an example of how not to do mathematics -- the substandard article of the week. JRSpriggs 07:05, 21 June 2007 (UTC)

Somer pseudoprime

A "{{prod}}" template has been added to the article Somer pseudoprime, suggesting that it be deleted according to the proposed deletion process. All contributions are appreciated, but the article may not satisfy Wikipedia's criteria for inclusion, and the deletion notice explains why (see also "What Wikipedia is not" and Wikipedia's deletion policy). You may contest the proposed deletion by removing the {{dated prod}} notice, but please explain why you disagree with the proposed deletion in your edit summary or on its talk page. Also, please consider improving the article to address the issues raised. Even though removing the deletion notice will prevent deletion through the proposed deletion process, the article may still be deleted if it matches any of the speedy deletion criteria or it can be sent to Articles for Deletion, where it may be deleted if consensus to delete is reached.

I'm including this warning here rather than on the page creator's page because the creator was an anonymous IP address that hasn't been active since 2005, and since it's likely to get more appropriate attention here. —David Eppstein 04:06, 20 June 2007 (UTC)

The article has an OEIS link; A085046, which is noticeably better than our article in explaining these. They alternate between odd squares and (even squares minus one); I have no idea why they're called pseudoprimes. I am not tempted to contest. Septentrionalis PMAnderson 17:54, 20 June 2007 (UTC)

Well, we need to be careful about allowing entries that are only sourced by OEIS. I've learned something about their process from someone who accepted and edited submissions. They basically accept any sequence that people submit. In some cases, cranks will submit some semi-garbage, and then the editors and some others can clean it up into something reasonable. They aim to collect all interesting number sequences. Wikipedia has a different goal. We generally want recognized scholarly work. --C S (Talk) 21:58, 20 June 2007 (UTC)

I don't see how the formula in the article generates A085046, and looking at A085046 I don't see why these should be called pseudoprimes. All but the first two are composite: either D² or D²−1. And what has Somer (Lawrence Somer?) got to do with this? What does it mean that the only Google hits for "Somer pseudoprime" are to this article?  --Lambiam^Talk 23:28, 20 June 2007 (UTC)

There's a typo in the formula; someone got confused by the even or odd case. Chan-Ho's explanation seems good for the absence of hits. But if it's going away, why worry? Septentrionalis PMAnderson 18:26, 21 June 2007 (UTC)

Non-universality in computation on AFD

I've nominated Non-universality in computation for deletion. See also Wikipedia talk:WikiProject Mathematics/Archive 26#Help with article in "unconventional computation".  --Lambiam^Talk 13:04, 20 June 2007 (UTC)

User:Dhaluza has extended the discussion of this issue to the Village Pump. EdJohnston 18:52, 21 June 2007 (UTC)

Usage notes

Partial derivatives

I always write

${\frac {\partial ^{2}f}{\partial y\,\partial x}}$

rather than

${\frac {\partial ^{2}f}{\partial y\partial x}}$

Should we have a norm prescribing this usage?

Names and links

This was proved by Pincherle (1880).

I think the usage above makes sense only if the list of references has an item labelled

• Pincherle, S. "Blah Blah Blah", Journal of Whatever, 1880.

Opinions? Michael Hardy 18:49, 23 June 2007 (UTC)

I agree that a year in parentheses should always indicate a Harvard-style citation, and should be reworded ("by Pincherle in 1880") if it is meant to just make a claim about a year. — Carl (CBM · talk) 19:36, 23 June 2007 (UTC)

Just as an additional note for those who don't already know (I found out about this combination of templates only this week), {{citation}} and {{harv}}, {{harvnb}}, and {{harvtxt}} work well together to make Harvard-style citations. As in {{harvtxt | Pincherle | 1880}} and {{citation | last = Pincherle | first = S. | title = Blah Blah Blah | journal = Journal of Whatever | year = 1880}}. Advantages of doing it this way over formatting it manually are that it's likely to be more consistently formatted, that it generates COinS metadata, and that the Harvard citation in the text gets html-linked to the appropriate line in the references. The different harv templates produce different formatting, but the one here with only the year in parens is {{harvtxt}}. —David Eppstein 20:19, 23 June 2007 (UTC)

Is this templatic synergy worth mentioning at or near Wikipedia:WikiProject Mathematics/Reference resources#Citation templates? I never use Harvard style myself.  --Lambiam^Talk 04:20, 24 June 2007 (UTC)

Added --Cronholm¹⁴⁴ 05:10, 24 June 2007 (UTC)

Apparently I've been too subtle. I've been using and promoting the Harvard citation templates for some time now. (See "area of a disk" and "integral", for example.) I like them for all the reasons David mentions, and because one template handles books and journal articles and everything else. (I'm also familiar with a weakness or two.) They definitely deserve an explicit mention at reference resources.

<soapbox>For web pages especially, Harvard style is superior to footnotes. On a printed page, moving the eyes suffices to read a footnote, yet it's still a distraction from the flow of the text. On a web page, hover popups or sidenotes would be the closest equivalent, but we don't have those and we'd have to train users to hover. Web "footnotes" are a misappropriation of a print idea; the to-ing and fro-ing is awkwardly jolting. (Properly, they're "endnotes".) As well, Harvard references often tell me enough from just the author(s) and date when I'm reading in a field I know, whereas a mere number tells me nothing; thus even in print Harvard style can be less distracting. Harvard style takes more space at the point of reference, which has the benefit of highlighting the absurdity of flurries of footnotes.</soapbox> --KSmrq^T 05:51, 24 June 2007 (UTC)

Some featured articles, or are they?

In response to a request made some time ago, I have, from time to time, been checking unsigned ratings and signing and dating them.

In the course of doing this I found a few FA-Class articles which don't, in my opinion, currently meet the featured article criteria (which is a requirement for FA-Class in the grading scheme). The articles I have in mind are Cryptography, Galileo Galilei and Monty Hall problem, which I reckon are about Bplus-Class.

Now I can't sign a rating I don't agree with, and I don't want to pass them over. Does anyone think these meet the criteria? Geometry guy 12:39, 23 June 2007 (UTC)

PS. There are also a few good articles I am not sure about: see Nash equilibrium, Best response and Probability theory.

PPS. Category:Mathematics articles with no comments now has less than 200 articles in it, so why not take a look and sign a maths rating today! :)

For the featured articles at least, there are links from the talk page to the discussions when the FA status was granted or reviewed. Those discussions may provide insight into what problems were seen during the review. You can always nominate an FA article for review, but that will be more beneficial if you're willing to stay with the review and fix the issues raised, since the reviewers are often reluctant to make even trivial changes themselves. — Carl (CBM · talk) 14:30, 23 June 2007 (UTC)

The problem here is that FA standards have changed so much even in the last year, and only Monty Hall problem has been reviewed recently. This last review began with an unedifying argument over inline citation and never fully recovered in my view, although a lot of effort was poured into copyediting. I'm reluctant to take it to FAR or GA/R again, although reviewers at the latter are working on improving their process, and do now quite often make edits to articles themselves. Geometry guy 15:44, 23 June 2007 (UTC)

Concerning Cryptography, I've found your (signed) comment a bit, ahem, cryptic. Plenty of inline citation, and what about the lead? Arcfrk 05:21, 24 June 2007 (UTC)

Yeah, it is a bit. I'm getting into the bad habit of thinking everyone knows WP:LEAD back-to-front. But forget about what I think, that isn't why I'm posting here. What do you think about the article? Geometry guy 10:02, 24 June 2007 (UTC)

Some Good Articles, or are they?

In addition to Nash equilibrium, Best response and Probability theory, Sylvester's sequence appears not to meet the criteria. The problem is again the lead, which at the moment is a definition/first section, rather than an overview. This should be fairly easy to fix, but I think other editors may be able to do a better job than I can. Anyone? Geometry guy 15:28, 24 June 2007 (UTC)

I made another pass at Sylvester's sequence. Criticism welcome. —David Eppstein 15:56, 24 June 2007 (UTC)

Thanks David, that was quick! I never knew that the Sasakian Einstein metrics on spheres were linked to this sequence. Very nice. Geometry guy 16:30, 24 June 2007 (UTC)

E is for ugly

Another exiting post by me, everyone! E for some inexplicable reason is in quite a poor state. Here are some things I have found:

Lie groups

These are not problem articles but all of the polytope articles are stubs.

• E6 (mathematics), E6 polytope
• E7 (mathematics), E7 polytope
• E8 (mathematics), E7½, E8 lattice, E8 manifold, E8 polytope

Is some kind of merger in order?

I thought of proposing a merger of some of the polytope articles in the past. A similar case is the various hyperbolic tessellation articles (see the Order_*_tiling articles in Category:Tiling). These remind me of Wikipedia's zoology articles: nice infoboxes on stub articles, with information presented clearly and uniformly. Maybe it's better to have a broader discussion on polytopes, tilings, and other articles of the mathematical "zoo" independently of the fact that the above examples happen to start with the letter E. Silly rabbit 10:24, 24 June 2007 (UTC)

Yes, I believe that would be appropriate, E just happened to be the catalyst. To start things off, should there be a merger? or are the free-standing stubs just an inevitability?--Cronholm¹⁴⁴ 10:32, 24 June 2007 (UTC)

Short answer: no.

Long answer... My point of view on this is that there is a clandestine WikiProject out there, which I will call WikiProject:Polytopes and tilings, which, for reasons known only to itself, wants every polygon, polyhedron, polychoron, tiling, tessellation or lattice, no matter how regular, irregular, stellated, or truncated, to have its own article. As Silly rabbit notes, WP:PAT have generated a lot of uniformly presented information, with nice infoboxes and classification tables.

I think it is inevitable that there will be such articles. They have a certain taxonomic appeal. Some of the information is arguably indiscriminate rather than encyclopedic, but I would rather not worry about it. If we merged En polytope into En (mathematics), we may well be depriving WP:PAT of three of its most notable articles.

So, when I see an article on a polytope or a tiling, I think to myself, "that is part of WP:PAT", then move quietly on.

Most other mergers of the above are untenable: the five exceptional Lie algebras/groups/root systems are distinct and notable enough to deserve separate articles, and the E8 lattice is a key building block in the theory of unimodular lattices. Geometry guy 11:09, 24 June 2007 (UTC)

Fair enough, I will treat WP:PAT articles the same way that I treat WP Numbers articles. I will think to myself "my goodness, that seems rather indiscriminate...oh well" and move on :)--Cronholm¹⁴⁴ 11:17, 24 June 2007 (UTC) P.S. Even E 7.5 is unmergeable?

Many of the tessellation articles are unreferenced, although most could probably be referenced with Grunbaum's "Tilings and patterns" tome. I don't have a copy at my disposal at the moment, but I have written Template:Grunbaum which optionally accepts a |pages= and/or |chapter= option. So if anyone wants to tackle these articles, please do so. (Note: I don't know for how long Template:Grunbaum is going to be allowed in the main space, so use subst.) Silly rabbit 11:23, 24 June 2007 (UTC)

Hi. I can't tell if I'm making anything worse on the E groups, but I'm coming from the polytope side, and just added a sort of "family" page at: Semiregular_E-polytope. I'd definitely prefer to keep polytope pages separate, mostly because there's a whole family of uniform polytopes with each semiregular form. Tom Ruen 02:46, 12 July 2007 (UTC)

Should they be listed?

• Ecliptic latitude, Ecliptic longitude
• Eddy covariance
• Edge of chaos
  • Notable popular idea in complex systems theory. I don't see the problem? -- Jheald 11:20, 24 June 2007 (UTC)
• Edgeworth conjecture
• Early stopping
  • Notable mathematical method (well, hack) in training neural networks. I don't see the problem? -- Jheald 11:20, 24 June 2007 (UTC)

I think these mostly belong to the category of articles that are mathematical enough to be on the List of mathematics articles but not relevant enough to WPM to need a maths rating. The one I'd be most tempted to rate is Edge of chaos; the one I'd be most tempted to remove from the List of mathematics articles is Eddy covariance (check "What links here" for that one). Geometry guy 11:21, 24 June 2007 (UTC)

Okay, as long as we are fine with them being listed(I though maybe some of them had slipped through the cracks).--Cronholm¹⁴⁴ 11:26, 24 June 2007 (UTC)

Should they be prodded?

• Eclectic probability Probably not ;) although it might be worth an AfD to prod someone into sourcing it. Geometry guy 11:34, 24 June 2007 (UTC)
• Edge-to-edge tiling I merged this with tessellation. -- Jitse Niesen (talk) 09:59, 24 June 2007 (UTC)
• Edmonds matrix No. Reference provided, definition expanded slightly. Notable (but will likely never be more than a stub). Silly rabbit 09:48, 24 June 2007 (UTC)
• Edmond's algorithm No. A quick googling for the reference Edmonds, “Optimum Branchings” establishes some degree of notability for this algorithm (the paper is referenced quite often).

Okay then, I will try to expand it. Does anyone have a copy of his original paper? It was published in the journal of research for the national bureau of standards, I think.--Cronholm¹⁴⁴ 09:57, 24 June 2007 (UTC)

• Effective descriptive set theory. And risk upsetting both Trovatore and CBM (who have both edited the stub)?! Not a wise move... :) Geometry guy 11:34, 24 June 2007 (UTC)

You don't have to worry about upsetting me, at least, but this article is a shame. EDST is an extremely important branch of contemporary set theory but our coverage is minimal. For example we don't have an article on Glimm–Effros dichotomy, a result on simple invariants (or lack thereof) in mathematics. Trovatore is an expert in the area, but I'll take a stab at expanding the article myself. — Carl (CBM · talk) 13:06, 24 June 2007 (UTC)

Thanks Carl - of course I was joking: what I was really saying, beneath the attempted humour, is that if you and Trovatore have both edited it, then it is obviously an important topic and so doesn't need to be prodded. Bon courage with the expansion! Geometry guy 14:32, 24 June 2007 (UTC)

• EGARCH. Merge with GARCH? Geometry guy 11:36, 24 June 2007 (UTC)
• Effective results in number theory Most certainly, not! Arcfrk 09:01, 24 June 2007 (UTC)

Fair enough, Suggestions? .Notable sources? It hasn't changed much since 2003(!). I can go Googling and JSTORing but it would be good if I had an author or two. --Cronholm¹⁴⁴ 09:09, 24 June 2007 (UTC)

Note that the absence of references in an article is in no sense a justification for deletion!

The article has an identity crisis, and you should ask Charles Matthews, who edited it recently, for suitable references. Lang's Diophantine Geometry would be good as a general reference. Arcfrk 10:13, 24 June 2007 (UTC)

Are you referring to Lang's Survey of Diophantine Geometry or are there two different books? I will ask him (BTW, the threat of deletion is a great motivator, notice that no one has commented anywhere but the prod section...sigh, I merely propose that the articles be proposed to be deleted, if no one comments like at Jarnik's theorem, then I PROD them)--Cronholm¹⁴⁴ 10:30, 24 June 2007 (UTC)

• Effectively calculable

I've added two clean-up tags to this. CBM has edited it, and may be able to come up with references. Geometry guy 11:41, 24 June 2007 (UTC)

I merged it with Church-Turing thesis. The term is rarely used anymore except in that context, and the article was really just a poor version of the Church-Turing thesis article. — Carl (CBM · talk) 13:06, 24 June 2007 (UTC)

Merger? + poorly written

• Ecological correlation, Ecological fallacy
• Edge-transitive, Edge-transitive graph

This one is the usual distinction between geometric things with edges (polyhedra, tilings, etc) and combinatorial things with edges (graphs), visible also e.g. in the split between vertex (geometry) and vertex (graph theory). It doesn't help that the polyhedron article links to the MathWorld graph article... Any attempt to merge the two article would have to wrestle with some subtle definitional differences, e.g. one can have a polyhedron with an edge-transitive graph as its skeleton that is not edge-transitive geometrically (simplest example: a scalene triangle). —David Eppstein 10:40, 24 June 2007 (UTC)

---

I am only 50 articles in so there is more to come. :)--Cronholm¹⁴⁴ 08:28, 24 June 2007 (UTC)

By the way, I am willing to make most/all of these changes myself, I just need direction and consensus before editing, I would like a little more participation than at the J articles(are my constant posts scaring you away? :( ). Anyway, Cheers--Cronholm¹⁴⁴ 08:38, 24 June 2007 (UTC).

As for constant posts, if others feel it is too much the details could be moved to a project subpage, but I think this is an appropriate place to look for comments. You might also look through User:VeblenBot/Oldpages which lists some pages that have not been edited for over a year. — Carl (CBM · talk) 13:06, 24 June 2007 (UTC)

Cool link, :) but you know this just means more delightful comments from me. In all seriousness though, I plan to go through every math article pruning and posting as I go. I imagine this will take several months but the combined effect could burn people out(including me). The only worry that I have is that a subpage will go the way of the dodo and the math portal. I think that I will wait and see how it goes. In any case, I plan to post fewer articles next time. --Cronholm¹⁴⁴ 13:19, 24 June 2007 (UTC)

Rumours of my extinction have been greatly exaggerated. The Mathematics Portal 14:35, 24 June 2007 (UTC)

AFD on Probability derivations for making low hands in Omaha hold 'em

This looks like it might be a fairly interesting AFD discussion. I expect there may be conflicting opinions even among members of the WikiProject, so I thought I would advertise it here. --C S (Talk) 14:34, 24 June 2007 (UTC)

BibTex for Wikipedia?, the second

After the discussion a couple of days ago, I programmed a database to facilitate the creation and use of consistent and correct and complete references like this (automatically generated) one:

Eisenbud, David. Commutative algebra with a view toward algebraic geometry. Heidelberg, New York: Springer-Verlag. ISBN 0-387-94269-6. {{cite book}}: Check |authorlink= value (help)

You may find the first result of these efforts here.

Right now, there are three intertwined databases, one for books, one for authors and a third one for publishers. The design of the database is intended to meet the needs of WP references, e.g. books are linked to their (co)authors etc., hence wikilinks to authors will appear (if there are any). Besides this, the main distinction between the database and this Template of User:Diberri is, that one may look up a book by its title, which seems more reasonable than by its ISBN.

I think, at the current state it's reasonable to call this a feasibility study. I would like to hear people's ideas about it, whether it's a reasonable thing to pursue further. Obviously, right now the database is practically void, so besides further programming (which I volunteer to do), it needs willing people to inhale life to it, i.e. data. This may probably be done automatically or semi-automatically, using the references which already exist in WP articles (or Math articles or whatever). At the moment this latter feature is not yet programmed, other reasonable things like looking up the ISBN database when one has the ISBN of a book, adding a similar database for articles in journals etc. are also not yet done. If the database is considered to be useful to you guys, I will implement these shortly, as well as other ideas emerging of your impressions. So, tell me what you think. Thanks. Jakob.scholbach 03:41, 18 June 2007 (UTC)

I think this is a great idea and would encourage you to continue the feasibility study, especially methods for the the automatic and semi-automatic population of the database. I suggest it be developed into a "proof of concept" for mathematics articles. Geometry guy 12:56, 18 June 2007 (UTC)

This is great indeed, a true database fillable by editors. Much better than everybody keeping their own subpages.

A somewhat related comment is that today I found out that one can get BibTeX info from Google Scholar (one has to enable one's preferences to see a link to BibTeX citations for each search result). This can be great help when writing papers. :) Also, it is easy to write a script to convert BibTeX to {{cite book}} format, although the quality of the result won't be high (no ISBN, last name/first name order, etc.). Oleg Alexandrov (talk) 02:00, 19 June 2007 (UTC)

I haven't looked at the details of any of this, but let me just voice my support for something like BibTEX for Wikipedia. Loisel 02:03, 19 June 2007 (UTC)

Thanks. Is it possible to parse the Mathematics WP articles and automatically retrieve all the contained references? Jakob.scholbach 17:04, 19 June 2007 (UTC)

It is, but there are others here with much expertise in this kind of thing who will be able to answer in more detail. You mught also find Wikipedia:WikiProject Mathematics/References useful. Geometry guy 18:50, 19 June 2007 (UTC)

In fact, I suggested this some months ago, and Carl seemed willing to help (though he has since become an admin, so may be frittering away his time in other ways now).

I do hope this project succeeds magnificently. And it would be such sweet irony if we mathematicians, who have so vigorously opposed the inline citation squad, are the ones to bring easy, reliable citations to Wikipedia. :-) --KSmrq^T 00:13, 20 June 2007 (UTC)

I can provide, on demand, a list of all the contents of all cite templates used on math articles or the contents of all references sections of math articles. The more difficult thing would be processing this data into a database. I'm sure many sources are duplicated, likely with errors in some, and it would take a lot of manual effort and verification.

Let me also point out User:VeblenBot/Unreferenced, a list of math articles that an automatic scan thinks have no references or external links section. — Carl (CBM · talk) 01:20, 20 June 2007 (UTC)

When you say "all cite templates", does that include {{citation}} templates? (I hope!) --KSmrq^T 02:58, 20 June 2007 (UTC)

OK, good. I will get back to you, Carl, when I'm done with the programming necessary prior to this. Jakob.scholbach 02:03, 20 June 2007 (UTC)

Jakob, please take your time, I can do it whenever. Ksmrq, yes, I can pull any template(s) you're interested in. The most difficult thing is just downloading all the math articles. — Carl (CBM · talk) 20:48, 20 June 2007 (UTC)

Can I say that I really detest the inversion of names in references? I really find it a negative, searching the site as much as I do, to have to search "Gauss, C. F." and so on with all the variants of "C. F. Gauss". In other words, it doubles what you have to do with an exhaustive search. The virtues of inversion seem to be mostly in the world where one does searches by scanning down columns. In other words, this is a paper habit. Charles Matthews 21:01, 25 June 2007 (UTC)

Yes, this is probably something you should tell those guys developing the {{citation}} template and the other ones. I find it somewhat natural to sort a list of references by the last name of the author, though. As far as the database is concerned, first and last names will be stored separatedly, so any reasonable formatting will be possible to implement. Jakob.scholbach 22:05, 25 June 2007 (UTC)

Links to natural topology

A certain User:Karada has been linking every occurrence of the phrase natural topology to the non-existent article natural topology. I've reverted a few of them, but there are many more articles to go through. To the best of my knowledge, natural topology typically does not have a prescribed meaning (in the sense of natural transformation) although I can easily imagine some uses where the term is "natural" in the categorical sense. Since there is no article on the subject, is there a consensus here that these edits should be reverted? Silly rabbit 19:50, 24 June 2007 (UTC)

Another possibility is to write an article, such as natural (mathematics) covering the basic (imprecise) uses of the word natural in mathematics. I have no idea what such an article might look like, though. Thoughts? Volunteers? Silly rabbit 20:02, 24 June 2007 (UTC)

Thank you for your comments. "Natural topology" seems to be, at the very least, a mathematical jargon term, like "up to", with a specific meaning in topology, even if it does not have a precise formal meaning. If we can't explain what we mean by this, we are doing our readers a disservice. If it hasn't got a meaning which can be articulated, we shouldn't be using it at all.

The problem is that the phrase "natural topology" is used, but nowhere defined, throughout many topology-related articles, and is indeed used in ways specific enough to be able to write papers with titles such as "There is no natural topology on duals of locally convex spaces" [54]. Clearly, "natural topology" must mean something in this context, or the paper wouldn't get published in a peer-reviewed journal: but what? Saying "it's informal" is like saying "it's a secret, we can't tell you", or "we're handwaving here, please ignore this bit" or "oh dear, did you miss that lecture?".

It's clear that "natural" means something a bit more precise than just "obvious" or "simple" in this context: if it just meant something as subjective as "obvious" or "simple", it would be hard to talk about the nonexistence of such a topology in a mathematical paper. From what I can see, "natural" must have a specific (even if informal) meaning in the context of topology.

My best guess is that "natural" in this context means something like "induced by the partial order(s) used in the construction of this structure". Is this correct? If not, can we find someone who does know what "natural" means in this context? -- Karada 20:17, 24 June 2007 (UTC)

I think it's usually a bad idea to write such articles, but if our hand is forced, then we have to be very upfront and clear about the fact that the term has no precise meaning (and hope no one asks for a citation, because hardly anyone bothers to note explicitly that terms with no precise meaning have no precise meaning). This is a very dangerous situation and can easily result in disaster articles like definable real number that can neither be easily fixed nor deleted. --Trovatore 20:27, 24 June 2007 (UTC)

Thank you! That's exactly what I was trying to get at by making those links. Either "natural" in this sense has a precise meaning, or it doesn't, and if it doesn't, its meaning should either be be possible to explain as a piece of informal jargon, in an article similar to "up to", or the usage should be avoided entirely, and the articles in question reworded to be more precise, more newbie-friendly, or both. -- Karada 20:31, 24 June 2007 (UTC)

By the way, if by chance Karada is right and the paper from the Springer journal does intend a precise meaning for the phrase "natural topology", then it must be a meaning from some specific subfield of functional analysis, and any article written about it should have a title with a parenthetical disambig phrase for that subfield. Otherwise there's the danger that the usual usages of the phrase, which have no precise meaning, will be inappropriately linked to the article for that precise meaning. --Trovatore 20:35, 24 June 2007 (UTC)

Here's an example: Wikipedia's ordinal number article contains a sentence that says, in full, "Ordinals have a natural topology." Now, that either means something precise, or it doesn't. If it means something formal, we should be able to create a natural topology article, about the subject of that sentence. If it means something informal, we should say that in sufficient detail for it to be understood. (Could this mean something like "A very simple topology can be induced on the ordinals using the 'greater than' order relation between them, and this is generally referred to by mathematicians as their 'natural' topology"?) For other examples of similar usages throughout Wikipedia, please see Special:Whatlinkshere/Natural_topology -- Karada 20:40, 24 June 2007 (UTC)

It is a worthwhile term: the point is to make a particular map or collection of maps continuous. Often there is a "best" topology which does this. I've made a start. Please expand and add your own examples. Geometry guy 20:53, 24 June 2007 (UTC)

G-guy, I really think that was a bad idea. The problem with writing articles on imprecise terms is it tends to make them seem more precise than they are. You may think you've abstracted the commonality from the varied usages and made them genuinely precise, but that's original research. I think the best course of action now would be for you to request deletion of the new article -- if no one else has yet edited it, that can be done without further formalities. --Trovatore 20:56, 24 June 2007 (UTC)

Any ambiguity and imprecision does not rest with this article. The article could actually be made quite precise, and it reflects most standard usages of the term. The imprecision rests with question "what are the natural operations or maps in a particular context": I certainly would not want to write an article on that (an overarching statement here surely would be original research). So I don't see the need for {{db-author}} right now, but thank you for the suggestion: if no one has anything further to say on the topic, it might be useful. Geometry guy 21:06, 24 June 2007 (UTC)

PS. If everyone here things that the idea of a "natural topology" as the finest or coursest topology (if such a topology exists) that makes a map or collection of maps continuous is original research, please let me know, and I will write a paper on it and send it to a top journal. God knows, I need the publications... Geometry guy 21:36, 24 June 2007 (UTC)

In that paper, it probably wouldn't hurt your reputation as a topologist to spell "coarsest" correctly. Michael Hardy 22:00, 24 June 2007 (UTC)

Thanks! Luckily, I'm not planning to build a big reputation as a topologist, but at least I spelt it right at natural topology. Geometry guy 22:28, 24 June 2007 (UTC)

PS. Hmmm, I see the latter is only right because someone else fixed it. I must be losing my mind. Can someone recommend a good clinic? Geometry guy 22:35, 24 June 2007 (UTC)

Just because something is imprecise, doesn't mean we can't have an article about it, even in mathematics. Handwavey ideas like up to are perfectly useful, even if it needs to be explained that they are informal; indeed, an article which explains that it is not a precisely defined term, and how and why it is used informally, seems to be just what is needed here to help the baffled beginner.

And, reading the comments above, we probably need to go further and have an article about natural operation as well, even if it has to explain that it is a jargon term with no formal meaning, and is the subject of great debate among mathematicians as to whether it has one at all. -- Karada 21:09, 24 June 2007 (UTC)

That's an easy redirect: the most common (i.e., sourced) way to make this precise is the notion of a natural transformation. Geometry guy 21:17, 24 June 2007 (UTC)

A few thoughts:

• I hope everyone here understands that, just because something is "original research" in the WP sense, that doesn't mean it's original enough to publish. In context it means it's going outside the encyclopedist's purview, not that he's necessarily done anything very creative.
• Just the same, it is possible that I overreacted in this case. What I really want to avoid is a clusterf*** like definable real number, where you have a necessarily imprecise notion, used all over the place in the literature but with meaning entirely context-dependent, but where many of the authors seem to think it has a unique precise meaning and write as though it did.
• So for example large cardinal property is another concept where there is no generally accepted precise definition, but also little if any disagreement about whether an individual candidate qualifies as a large cardinal property, and it's too important to ignore. Is "natural topology" really in that category, or is it more or less just jargon?
• Finally, I disagree with Karada about the utility of jargon articles like up to. I think they're a blight. --Trovatore 22:06, 24 June 2007 (UTC)

I more or less agree with Trovatore that it is a bad idea to link every occurrence of natural topology with the recently created article. Nevertheless, I have reverted all of my reverts save one: Euclidean space, where I feel that "...the natural topology induced by the metric" is clearly what was intended rather than "...the natural topology induced by the metric". Let me say that, per Trovatore, I still object to a blanket decision on linking every occurrence of the term natural topology on Wikipedia to this particular article, though. In the case of Euclidean space, this is a detriment rather than an improvement to readability, for example. Silly rabbit 22:27, 24 June 2007 (UTC)

I agree with Silly rabbit's choice of links. Natural topology isn't a great stub, so I encourage editors to (a) improve it, and (b) link to it with caution. I still think it is an article worth having, though. Geometry guy 22:40, 24 June 2007 (UTC)

How about simply adding a few sentences to Mathematical jargon instead of creating an article? Arcfrk 23:37, 24 June 2007 (UTC)

After checking out a few of these links to Natural topology, I came to the conclusion that such blanket linking a is really bad idea, since no matter what is at that page, it would not help understanding the meaning of the linked terms in the instances that I've reviewed (which is frequently subtly or completely different). Or to put it differently, there is no such an overriding thing as Natural topology as far as these linked articles are concerned. Arcfrk 00:49, 25 June 2007 (UTC)

And now I've gone over all of them manually, and after checking that the linking is inappropriate in each case, unlinked. Arcfrk 01:22, 25 June 2007 (UTC)

My impression of the topic is that the meaning of "natural" is sociological or psychological: it has nothing to do with coarseness or making things continuous, it just means that there is one topology that most experts on the topic would pick as the most appropriate to use. I think that trying to nail the term down any further would be a mistake. The best we can hope for is a stubby article that says as much and points to a widely-varying collection of uses of "natural topology" in the literature to back up that point. But to do so would most likely be original research by synthesis. —David Eppstein 06:19, 25 June 2007 (UTC)

I'm glad you brought in original research by synthesis. That really brings the issue into focus for me. Linking natural topology to a particular use of the term would need to be cited, particularly for things like "the Zariski topology is natural" or "the Euclidean topology is natural". Both are true, but since neither is commonly introduced as a natural topology (in the strict sense), it would need to be referenced somehow. Silly rabbit 10:09, 25 June 2007 (UTC)

Long ago, I put the sentence "Ordinals have a natural topology." into the lead of ordinal number. It was not intended to be jargon or to have any formal definition. I was just putting the reader on notice that there is a topology which has a special relationship to ordinals. The details are covered in a section further down in the article (now farmed out to order topology#Topology and ordinals). Karada (talk · contribs) linked "natural topology" to his new article natural topology. Arcfrk (talk · contribs) reverted that and added a comment saying "This is an obscure claim. Are ordinals a topological space? Or even a set? What is the topology? Needs a bit of clarification." which shows a lack of understanding of the topic. Tobias Bergemann (talk · contribs) reverted that and changed the sentence to "Any ordinal number can be made into a topological space by endowing it with the order topology." which is correct, but not appropriate for the lead since it will scare off unsophisticated readers. JRSpriggs 09:27, 25 June 2007 (UTC)

Reply to JRSpriggs. I prefer the original version, but I see some logic in putting details in up front. Would a better way to say it be "Ordinals have a natural [[topological space|topology]]: the [[order topology]]. This seems less scary than the current revision, but has the advantage of saying what the "natural" topology is. Silly rabbit 09:35, 25 June 2007 (UTC)

A bit unclear, because ordinals don't form a set (which is what puzzled Arcfrk above): instead "Any ordinal has a natural [[topological space|topology]]: the [[order topology]]." Tobias Bergemann has just fixed it in a similar way, but avoiding the use of the word "natural" Geometry guy 10:49, 25 June 2007 (UTC)

Ha! Yes, that's what I meant. Not ordinals are a topological space, but any ordinal... (etc.) Silly rabbit 10:52, 25 June 2007 (UTC)

I wonder if it would help to keep in mind a distinction between "a natural topology" and "the natural topology". In quite a few contexts people write "Equip it with the natural topology". It seems to me that something quite specific is meant here, and a link to an article which explains that could be helpful. On the other hand, in the ordinal example, the language "any ordinal has a natural topology: the order topology" is quite different. Here we don't want to link to natural topology, only to topological space and order topology: if we had to link the word "natural", then probably the best we could do is link it to wiktionary!

PS. Just curious, and I haven't thought it through, but what are the left and right order topologies in this case? Geometry guy 11:05, 25 June 2007 (UTC)

An overexposure to category theory with its technical use of "natural" makes me automatically expect such a sense when I see the term in mathematics. Clearly, many authors do not bear that burden, and use the word "natural" as naturally as they breathe. An analogy, for those who do not relate to categories, is "group", which carries no technical meaning for a lay reader. I wonder if there are a multitude of such examples that we fail to see. I expect we will see more. --KSmrq^T 22:57, 25 June 2007 (UTC)

Lead

I have noticed lead problems with most mathematics articles, at least as far as the general editing advice at WP:LEAD goes. For instance, they often fail to give an adequate summary of the article. I realize that there are possibly good reasons for not abiding by some of the lead recommendations in many math articles in the spirit of Wikipedia:Make technical articles accessible. Does the math project offer any more specific guidelines on the lead? Silly rabbit 14:46, 25 June 2007 (UTC)

Yes, most mathematics articles do have lead problems. However, it is perfectly possible to have a decent article without satisfying WP:LEAD. Often the problem is purely cosmetic (e.g. the lead material really belongs in the first section, or the lead is a one-liner but the first section contains good lead material). Even if it isn't, an article which is accessible to someone is much better than no article at all. We have a lot of pretty decent B-Class articles, and for me, it is only really when we want to lift them to B+/GA-Class and above that issues such as the lead, and "is it accessible as it could be?" really start to bite. I'd be interested to know what other people think. Geometry guy 19:04, 25 June 2007 (UTC)

Perhaps we should start a new thread, since clearly my question doesn't have an easier answer (along the lines of "Why yes, SR. That was discussed 8 months ago in [this thread]. See [this new policy recommendation].") A case study is my recent foray into bringing exterior algebra up to scratch. The lead has definite problems: it aims to give both a summary of the article and to be partially accessible to a general audience. I think its clear that these objectives are incompatible here (unless some more brilliant editor wants to take a stab at it.) Silly rabbit 20:08, 25 June 2007 (UTC)

For the exterior algebra, solution seems fairly obvious: delete the second paragraph of the lead and only keep a non-technical sentence or two from the third one, mentioning what additional structures are present on exterior algebra, possibly, emphasizing those applications where that structure is important. Also, what are the guidelines about citations from the lead? Arcfrk 20:19, 25 June 2007 (UTC)

In cases like this it sometimes helps to have an "Informal introduction" in section 1. If the lead is a summary then the accessibility of the lead should reflect that of the article. In other words, much of the lead should be as accessible as much of the article, but if there are important technical points or definitions, then I don't see why they can't also be mentioned in the lead.

As for citations, I've seen different things in different places. One argument is that since the lead should contain no information which is not expanded in the body of article, this information can be sourced there instead. The counterargument is that if any lead information is "likely to be challenged" it might be more helpful to provide a cite in the lead anyway. I guess this rarely applies in math though. Geometry guy 20:49, 25 June 2007 (UTC)

To me, WP:LEAD is a stylistic choice — there are plenty of other ways to begin a piece of expository material. But it's a stylistic choice that doesn't hurt us, I think, and one that's been made Wikipedia-wide, as part of a set of choices to make the content here more unified. Is there a good reason to depart from it for math articles? —David Eppstein 20:20, 25 June 2007 (UTC)

It is slightly more than a stylistic choice, because for some articles, the lead alone will be included in some fixed editions of Wikipedia. In any given article, though, there are good reasons to depart from it initially, in that one cannot write a lead for a stub, or for an article in development. However, once a mathematics article reaches about B-Class, it seems to me that its further development and WP:LEAD are perfectly compatible, and I agree that there is no reason to depart from the latter. Geometry guy 20:49, 25 June 2007 (UTC)

I'm inclined to say any mathematics article that begins with the word "Let..." is horribly wrong in its intro. My favorite example of this sort of thing remains an article on something other than mathematics. It's called schismatic temperament. Given the usual meanings of those two words, I guessed that it was about a psychiatric disorder. Nothing in the first sentence (when I first looked at it) told the lay reader that it was not about chemistry, politics, fiction writing, etc. I changed it so that it starts with the words "In music,...". Such a brief phrase, but worth a lot. (Of course, there's more to lead sections than that.) Michael Hardy 22:35, 26 June 2007 (UTC)

… and here is the diff: [55] The article looks way better now Arcfrk 00:12, 28 June 2007 (UTC)

New nav template on logic articles

User:Gregbard has created a new {{Logic}} template and put it at the bottom of some logic articles, including a few in math logic. Now, I have to say it's quite a bit slicker than the navigational templates we've seen in the past. It's relatively unobtrusive, just a thin horizontal bar across the bottom of the article with a "show" button in the right-hand corner. If you click on "show" it pops up a bunch of subfields and related articles.

There's at least one of his categorizations I don't entirely agree with, but that can be dealt with. The question is, is this sufficiently different from the nav templates we've rejected in the past, to reconsider whether to allow it? I'm undecided myself. --Trovatore 08:58, 27 June 2007 (UTC)

I like show/hide wikitables, and I think this is a very appropriate use of them. I don't know what arguments have been made in the past, but in my view, navigation templates are not entirely encyclopedic content because they "label" the article and link to other articles without providing relevance or justification: they provide a "See also" section with no option to prune the list. On the other hand, for many readers, they are a great convenience. So I find a "collapsible collapsed" navigation template a nice compromise: unobtrusive, but available. I think we should consider doing that with more of our navigation templates: it is quite straightforward to add this functionality. Geometry guy 17:30, 27 June 2007 (UTC)

Hack attempts/paranoia

I've recently started to receive emails containing "temporary passwords" to my WP login account. I beleive that these are what one gets if one checks the "I forgot my passord" box on the WP login page. As it happens, I haven't forgotten it, and someone else is making these requests. Being slightly paranoid, I am concerned that someone is hoping to catch one of these emails in-flight (they're mailed out in cleartext, so the temporary password is clearly visible), and is thus hoping to hack my account. Any recommendations on how I should deal with this? Ignore? Retry? Abort? linas 23:56, 27 June 2007 (UTC)

I don't know how anyone could catch one "in flight" unless they have access to your ISP or a major carrier, in which unlikely case you aren't safe anyway. More likely they are just trying to annoy you. You can ignore the emails and use your ordinary password. — Carl (CBM · talk) 23:59, 27 June 2007 (UTC)

This is definitely worth reporting to someone who can look into the source. Depending on where you read your mail, there might be an easy way for someone to tap communications close to you. But even if your account is never compromised, the attack (if that's what it is) bears investigation. And if it is not an attack, but a piece of misbehaving software, that is still worth investigating. I wish I could tell you who to contact, but this is new to me. --KSmrq^T 04:52, 28 June 2007 (UTC)

I came across this before when the attack was malicious. I seem to recall that the IP responsible was blocked WP:AN/I is probably your first place to look for assistance. --Salix alba (talk) 07:36, 28 June 2007 (UTC)

It is that time of the month again

Hey everyone, June is almost over and it is time for a new collaboration of the month WP:MATHCOTM and we need some votes so we can decide what article will receive this high honor. Mosey on down and place your vote or go ahead and suggest a previously unlisted article, all contributions are welcome!--Cronholm¹⁴⁴ 22:15, 28 June 2007 (UTC)

P.S. I think this diff [56] demonstrate the raw power of a good collaboration. Thanks again to everyone who worked hard on Integral

Symplectic geometry or symplectic topology?

I have discovered, to my great surprise, that there is no Category:Symplectic geometry. All symplectic articles are being filed under Category:Symplectic topology instead, even though the vast majority of them is really about geometry. I was wondering what people here think of renaming the category? Arcfrk 06:12, 26 June 2007 (UTC)

I agree with the rename. Symplectic topology is an important modern branch of symplectic geometry. In the long run, I expect it will make a good subcat. Also note that the same issue applies to the Symplectic geometry article, which is currently a redirect! Geometry guy 09:14, 26 June 2007 (UTC)

This is priority one on my to-do list, but until I graduate, I can't justify writing articles for Wikipedia when I should be writing my dissertation!  :) (I shouldn't even be checking my watchlist as often as I do.) But if anyone has the drive, time, and energy now, more power to you. VectorPosse 18:20, 26 June 2007 (UTC)

Nonsense. No one outside your thesis committee is likely to read your dissertation, and they may not read all of it; but people all over the world and for years to come will read your Wikipedia contributions! Besides, once you have your sheepskin in hand, you'll likely be employed as an assistant professor whose tenure track duties include trying to teach first-year calculus to students who don't want to learn it. After a year or two of that you may not wish to explain anything to anyone who is not already a mathematician. ;-D --KSmrq^T 23:29, 26 June 2007 (UTC)

Disturbingly close to the truth, I'm sure. Hopefully the world will not have to wait more than a few more months! VectorPosse 07:46, 27 June 2007 (UTC)

If getting a diploma were fun, everbody would want one. But do not despair. Some students will be like you; they will be bright and curious and motivated and will inspire their teachers. You may find it refreshing to relate to faculty as a colleague rather than as a student. You can start paying off debts instead of accumulating more. Besides, is it so bad to hope that your thesis is not the best work you will ever do? :-D --KSmrq^T 08:21, 27 June 2007 (UTC)

Very wise! Meanwhile I think we should rename the pages/categories as recommended. Geometry guy 22:43, 26 June 2007 (UTC)

Yes, this part should be pretty easy to take care of for now. What I had in mind for the (hopefully) near future is a complete rewrite of all this stuff (on the symplectic and contact side—the issues are similar for both). VectorPosse 07:46, 27 June 2007 (UTC)

Oleg has suggested to me that for a rename, it would be best to take the category to CFD. An alternative would be just to create Category:Symplectic geometry and make Category:Symplectic topology (which doesn't have much edit history) into a subcat. Any preferences? I'm happy to do the CFD nomination if that is what people prefer. Geometry guy 16:17, 27 June 2007 (UTC)

Best just to do it. It's a bit technical for CfD, and everyone here seems to think it's pretty uncontroversial good sense. Best just to be bold and go ahead. Jheald 16:33, 27 June 2007 (UTC)

Yes, but do what? I have change the cats in all symplectic geometry articles which are not symplectic topology. So do we move Category:Symplectic topology, or create Category:Symplectic geometry. My own preference is for the move, to preserve the (admittedly small) edit history. We can then decide whether we want Category:Symplectic topology to remain as a subcat. However, the move needs an admin, which I am not. Geometry guy 19:57, 28 June 2007 (UTC)

I'd just create a new one, and in the new edit summary say where you're pulling over some of the text from. We pull text over from one article to another all the time - no difference here. That way seems much the simplest. Jheald 20:05, 28 June 2007 (UTC)

I thought the point was that Dusa McDuff said the subject could now be called symplectic topology; and many people were going along with that. Just creating a supercat Category:Symplectic geometry, and moving out things that would be annoying to have in Category:Symplectic topologyy, seems an obvious solution. Charles Matthews 14:04, 29 June 2007 (UTC)

Duplication of adjoint representation

A discussion on the reference desk brought to my attention the existence of two similar articles: (1) adjoint endomorphism, to which "adjoint representation of a Lie algebra" redirects, and (2) adjoint representation. Could someone with a little time and interest look into this apparent duplication? --KSmrq^T 04:48, 29 June 2007 (UTC)

On the first glance, the first article is about the Lie algebra adjoint representation, and the second article is about the Lie group case. Arcfrk 05:20, 29 June 2007 (UTC)

And I suppose, in principle, we could have independent articles. However, these are closely linked, and I think both articles mention both concepts, and both cite Fulton & Harris, where Ad and ad appear together. Anyway, I'm trying to concentrate on integral as the end of the month fast approaches, and the last thing I need is yet another distraction. :-) --KSmrq^T 11:47, 29 June 2007 (UTC)

Residual sum of squares

This article has had a merge tag on for a while now, and it's beyond my knowledge to assess it. Could someone here take a look. Cheers Kevin 08:38, 29 June 2007 (UTC)

Jul 2007

Wikipedia talk:WikiProject Mathematics/Archive 27

Aug 2007

Wikipedia talk:WikiProject Mathematics/Archive 28

Sep 2007

Wikipedia talk:WikiProject Mathematics/Archive 29

Oct 2007

Wikipedia talk:WikiProject Mathematics/Archive 30

Nov 2007

Wikipedia talk:WikiProject Mathematics/Archive 31

Dec 2007

Wikipedia talk:WikiProject Mathematics/Archive 32